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THE   FLOWER  AND  THE   BEE 


f) 


Torch-Lily  or  Flameflower.     Kniphofia  aloides 
A  bird-flower  from  South  Africa  widely  cultivated  in  North  America 


THE 
FLOWER  AND  THE   BEE 

PLANT     LIFE     AND     POLLINATION 


BY 

JOHN  H.   LOVELL 

BOTANICAL    EDITOR    OF    THE    "a  B  C    OF    BEE    CULTURE' 


ILLUSTRATED   FROM    PHOTOGRAPHS    BY    THE    AUTHOR 


NEW    YORK 

CHARLES    SCRIBNER'S    SONS 

1918 


Copyright,  1918,  bt 
CHARLES  SCRIBNER'S  SONS 

Published  June,  1918 


PREFACE 

Many  books  have  been  published  for  the  avowed  purpose  of 
making  kno^Yn  our  wild  flowers.  For  botanical  students  there 
are  the  technical  floras,  and  for  those  not  familiar  with  botani- 
cal nomenclature  there  have  been  provided  various  artificial 
keys  to  our  common  trees,  shrubs,  and  herbaceous  plants. 
Formerly  the  study  of  botany  consisted  chiefly  in  *'the  mental 
gymnastics"  of  analyzing  flowers  to  determine  their  names, 
but  this  is  very  far  indeed  from  knowing  them.  The  identi- 
fication of  a  species  should  be  regarded  merely  as  an  introduc- 
tion and  the  beginning  of  a  friendship  long  to  be  continued. 
The  present  volume  treats  of  plants  alive  and  in  the  midst  of 
their  home  surroundings.  There  is  no  more  attractive  subject 
for  investigation  than  the  manifold  ways  in  which  flowers  have 
solved  their  life  problems,  and  have  made  use  of  both  inanimate 
and  animate  agencies  as  pollen-carriers.  The  practical  value 
of  such  observations  cannot  be  easily  overestimated,  since  they 
make  the  bee-keeper  familiar  with  the  resources  of  the  honey 
flora,  and  save  the  fruit-grower  from  great  disappointment  and 
loss. 

During  many  years  the  author  has  devoted  a  great  amount 
of  time  to  the  observation  of  the  life-relations  of  flowers.  The 
forms  and  functions  of  the  floral  members  have  been  carefully 
studied,  and  innumerable  hours  have  been  given  to  watching 
the  behavior  of  the  insect  visitors  and  collecting  them.      For 

™  89928 


PREFACE 

much  of  his  time  the  field  naturaHst  must  be  content  with  the 
companionship  of  Nature. 

"The  flower  that  on  the  loneh'  hillside  grows 
Expects  me  there  when  Spring  its  bloom  has  given; 
And  many  a  tree  and  bush  mj"  wandering  knows." 

The  most  important  of  insect  pollinators  is  the  honey-bee, 
and  in  order  to  become  familiar  with  its  economy  I  long  since 
became  a  practical  bee-keeper.  Thus  I  have  been  able  to  ap- 
proach the  science  of  flower  ecology  from  three  different  points 
of  vantage.  It  will  be  evident  in  the  following  pages  that  the 
botanist,  entomologist,  or  apiarist,  who  studies  only  one  phase 
of  this  subject  must  necessarily  obtain  only  a  partial  and  im- 
perfect view. 

As  a  result  of  the  supercritical  spirit  which  has  been  abroad 
in  the  scientific  world  during  the  past  generation  most  of  the 
older  biological  theories  have  been  called  in  question,  and 
many  new  and  bizarre  suppositions  have  been  advanced.  The 
experience  of  the  author  has  convinced  him  of  the  efficacy  of 
natural  selection  in  the  evolution  of  flowers,  of  the  advantages 
of  cross-fertilization,  and  of  the  inheritance  of  acquired  char- 
acters. In  the  absence  of  insect  visits  there  is  no  satisfactory 
evidence  that  conspicuous  flowers  and  their  adaptations  would 
ever  have  been  developed.  So  highly  improbable  and  quixotic 
are  some  of  these  new  theories  that  l)iologists  should  not  forget 
that  common  sense  is  an  important  factor  in  the  interpretation 
of  nature.  Let  us  not  mistake  for  giants  what  in  reality  are 
only  windmills. 

While  technical  terms  have  been  avoided,  great  care  has  been 
taken  to  secure  accuracy  of  statement.  Such  difficulties  as 
occur,  it  is  believed,  will  prove  stimulating  rather  than  dis- 
couraging.    Most  of  the  photographs  are  natural  size,  except 

viii 


PREFACE 

ill  the  case  of  a  few  of  the  larger  flower-chisters,  and  have  been 
taken  on  panchromatic  plates  to  preserve  in  monochrome  the 
proper  color  values.  A  small  stop  and  a  long  exposure  have 
been  employed  to  secure  details.  By  the  aid  of  the  figures  the 
reader  will  be  able  to  follow  the  descriptions  with  nearly  as 
much  ease  as  with  the  natural  flowers.  It  is  hoped  that  the 
volume  may  inspire  in  those  who  have  been  content  in  merely 
learning  the  names  of  flowers,  a  desire  to  know  more  of  their 
biology,  both  past  and  present,  and  that  in  the  schools,  on  the 
farms,  and  among  all  students  of  nature  it  may  awaken  a 
greater  interest  in  the  study  of  plant  life. 

Much  of  the  material  used  in  the  preparation  of  the  follow- 
ing chapters  has  appeared,  partly  in  more  technical  form,  and 
partly  in  popular  articles  in  the  American  Naturalist,  the  Jour- 
nal of  Animal  Behavior,  the  Scientific  Motithly,  Entomological 
Neivs,  Psyche,  Gleanings  in  Bee  Culture,  the  A  B  C  of  Bee  Cul- 
ture, A  Cyclopedia  of  Everything  Pertaining  to  the  Honey-Bee, 
the  America?!  Bee  Journal,  the  Lewiston  Journal,  etc.  Without 
this  long  preliminary  preparation  they  would  probably  never 
have  been  written.  Grateful  acknowledgment  is  also  made  to 
my  wife  for  assistance  in  statistical  and  entomological  work. 

John  H.  Lovell. 


CONTENTS 

CHAPTER  PAGE 

I.     Flowers  and  Humanity 1 

II.     The  Discovery  of  the  Secret  of  Flowers    ...  8 

HI.     Flowers  Pollinated  by  the  Wind 20 

IV.     Bees  as  Builders  of  Flowers 47 

V.     Bumblebee-Flowers 70 

VI.     The  Gathering  of  the  Nectar 89 

VII.     Bees  Which  Visit  Only  One  Kind  of  Flower    .  105 

VIII.     Butterfly-Flowers 125 

IX.     Nocturnal  or  Hawk-Moth  Flowers 139 

X.     Fly-Flowers 100 

XL     Beetles  and  Flowers 178 

XII.     Pollen-Flowers 193 

XIII.       Is    CONSPICUOUSNESS    AN    ADVANTAGE    TO    FlOWERS  .^        .  203 

XIV.     The  Colors  of  North  American  Flowers     .      .      .  221 

XV.     Bees  and  F'ruit-Growing 261 

Index 279 


ILLUSTRATIONS 

Torcli-Lily  or  Flanieflower Frontispiece 

FIGUHK  PAGE 

1.     Forget-Me-Not 11 

^.     Hermann  Mueller 15 

3.  Bladderwort 18 

4.  Common  Alder 2 '2 

5.  Bayherry 25 

().     Gray  Birch 2(> 

7.  Yellow  Birch 27 

8.  American  Elm 29 

9.  Cotton-Grass 31 

10.  Fringed  Sedge 33 

11.  Herd's-Grass 34 

12.  Quitch-Grass 35 

13.  Purple  Amaranth 37 

14.  Roman  Wormwood 39 

15.  English  Plantain 41 

1(5.     Red  Pine.     Staminate  cones 42 

17.  Red  Pine.     Ovulate  cones 43 

18.  Balsam-Fir.     Staminate  cones 44 

19.  Balsam-Fir.      Ovulate  cones 45 

20.  Blue  Violet 49 

21.  Pansy 51 

xiii 


ILLUSTRATIONS 

FIGURE  PAGE 

22.  Garden-Pea oS 

23.  Alfalfa 54 

24.  White  Clover.     First  stage 55 

25.  White  Clover.     Second  stage 57 

26.  Purple  Vetch 58 

27.  Two  varieties  of  Monkey-Flower 59 

28.  Yellow  Calceolaria 61 

29.  Yellow  Rattle 62 

30.  Heal-All 63 

31.  Pink-Fringed  Polygala 65 

32.  Pink  Lady's-Slipper 6G 

33.  Sheep-Laurel 67 

34.  Foxglove 68 

35.  Red  Clover .  73 

36.  Bee-Larkspur '^5 

37.  Monk's-Hood '^C 

38.  W'hite  Garden-Columbine 77 

39.  Tartarian  Honeysuckle '79 

40.  Snapdragon •      •  81 

41.  Turtle-Head 82 

42.  Jewelweed 83 

43.  Fringed  Gentian 85 

44.  A  Common  Bumblebee 86 

45.  American  Bumblebee 86 

46.  Buckwheat 91 

xiv 


ILLUSTRATIONS 

FIGHRE  PAGE 

47.  Bushy  Goldenrod 93 

48.  Tall,  Hairy  Goldeiirod 95 

49.  Cream-C(jlored  Goldeiirod 97 

.50.  Fly-Honeysuckle 99 

51.  Scarlet  Runner 101 

52.  Large  Insects  Captured  by  Crab-Spiders 103 

53.  Pickerel-Weed 107 

54.  Yellow  Water-Lily 109 

55.  Pussy-Willow Ill 

50.  Early  Goldenrod 113 

57.  Wild  Raspberry 117 

58.  Common  Solitary  Bees  of  the  Eastern  States     ....  123 

59.  Sweet-William 127 

CO.  Orange-Red  Lily 129 

Gl.  Canada  Lily 131 

02.  Orange-Red  Butterfly 133 

03.  Red  Phlox 135 

04.  Purple-Fringed  Orchis 137 

05.  Thorn-Apple 141 

GO.  Yucca  Whipplei  of  California 142 

07.  Twig  from  flower-cluster  of  Yucca  Whipplei 145 

08.  A  Hawk-Moth 147 

09.  Climbing  Honeysuckle 149 

70.  Evening-Primrose 151 

71.  Night-Flowering  Catchfly 152 

XV 


ILLUSTRATIONS 

FIGURE  PAGE 

72.  While  Catchfly .  153 

73.  Racemetl  Catchfly 154 

74.  Bouncing  Bet 155 

74a.  Night-Blooming  Tobacco 15(5 

75.  White  variety  of  Purple-Fringed  Orchis 157 

76.  Carrion-Flower liH 

77.  Purple  Trilhum 163 

78.  Water-Arum 165 

79.  Mountain  Saxifrage 166 

80.  Arum 167 

81.  Jack-in-tlie-Pulpit 169 

82.  Jack-in-the-Pulpit 170 

83.  Dutchman's-Pipe 171 

84.  Speedwell 172 

85.  Twinflower 175 

86.  Common  Milkweed 176 

87.  Beetles  which  never  visit  flowers 179 

88.  Choke-Cherry 181 

89.  Sheepberry 183 

90.  Common  flower-visiting  beetles 184 

91.  Blue  Flag 187 

92.  Beetles  with  a  tongue  resembling  that  of  a  l)utterfly  be- 

longing to  the  genus  Nemognatha 191 

93.  Wild  Rose 195 

94.  Mullein 197 

xvi 


ILLUSTRATIONS 

FIGTTKE  PAUE 

95.     Red  Poppy 198 

90.     Purple  Poppy 199 

97.  Common  Loosestrife 201 

98.  Bimehberry 204 

99.  Sunflower 205 

100.  Indian-Pipe 207 

101.  Bean 210 

102.  Purple  Coneflower 211 

103.  Borage 215 

101.  Diagram  of  the  "flower,"  or  strohilus,  of  CUjcadcnidea  daco- 

te?Lsis,  a  fossil  plant  from  the  Blaek  Hills,  South  Dakota  225 

105.     Yellowish-green  flowers  of  Rock  Maple 229 

10(5.     Woodbine 231 

107.  Cucumber 233 

108.  Garden-Marigold 235 

109.  Button-Bush 240 

110.  Carrot 241 

111.  Mayweed 243 

112.  Cardinal-Flower 249 

113.  Red  Maple 251 

114.  Purple  Vervain 255 

115.  Common  Pear 266 

116.  Keswick  Codlin  Apple 268 

117.  Apple-Blossom 269 

118.  Brighton  Grape 273 

119.  Strawberry 274 

xvii 


THE 

FLOWER  AND  THE  BEE 

CHAPTER  I 
FLOWERS  AND   HUMANITY 

DURING  the  past  half -century  we  have  been  learning 
as  never  before  in  the  history  of  the  human  race  the 
great  importance  of  keeping  in  close  contact  with  na- 
ture. Our  future  health  and  prosperity  depend  upon  our  love 
for  the  soil  and  its  productions.  The  Greek  fable  which  tells 
how  the  giant  Antseus,  while  wrestling  with  Hercules,  never 
failed  to  renew  his  strength  whenever  he  touched  his  mother 
earth,  will  always  be  true  of  man,  both  physically  and  morally. 
Of  all  natural  productions,  there  is  none  so  well  adapted  for 
maintaining  an  intimate  communion  with  nature  as  the  cul- 
tivation and  study  of  flowers.  Whoever  plants  a  flower- 
garden,  benefits  not  only  himself  but  his  whole  village.  If 
the  human  brain  is  the  most  wonderful  production  of  evolu- 
tion, as  Haeckel  asserts,  flowers  are  the  most  beautiful;  and, 
says  William  Winter,  '  the  ministry  of  beauty  is  the  important 
influence  upon  society  that  can  never  fail.' 

There  is  a  fascination  about  an  old  garden,  indeed,  that  few 
can  resist.  I  am  glad  that  the  first  botanical  garden  in  America, 
which  was  planted  by  John  Bartram,  the  first  American  bota- 

1 

O,  H.  HIUL.  LIBRARY 


THE   FLOWER  AND   THE   BEE 

nist,  is  still  preserved  as  a  public  park  by  the  city  of  Philadelphia. 
It  contained  a  great  variety  of  shrubs  and  trees,  as  well  as 
herbaceous  plants,  raised  from  seeds  and  roots  collected  during 
his  numerous  journeys  and  received  from  his  European  corre- 
spondents. There  was  a  greenhouse  built  by  Bartram  him- 
self, over  the  door  of  which  were  inscribed  the  lines: 

"Slave  to  no  sect,  who  takes  no  private  road, 
But  looks  through  nature  up  to  nature's  God." 

One  of  Bartram's  correspondents  was  Peter  CoUinson,  a 
London  merchant,  who  had  a  choice  garden,  the  pride  of  his 
life,  at  Mill  Hill,  where  he  skilfully  cultivated  rare  species  of 
plants  received  from  the  colonies.  In  one  of  his  letters  to 
Bartram  he  exclaims :  "  Oh,  Botany !  delightfullest  of  all  the 
sciences !  there  is  no  end  to  thy  gratifications."  No  one  who 
has  not  experienced  it  can  realize  how  intense  is  the  enjoy- 
ment of  watching  the  blooming  of  plants.  A  short  time  be- 
fore his  death  Keats  told  his  friend  Severn  that  he  thought 
that  his  intensest  pleasure  in  life  had  been  to  watch  the  growth 
of  flowers. 

Among  children  the  love  of  flowers  is  universal.  Says  one 
writer:  "I  think  I  never  knew  a  child  that  did  not  love  flowers. 
Many  children  are  passionately  fond  of  them,  but  I  never  knew 
a  child  indifferent  to  them."  Children  and  flowers !  Flowers 
and  children !  Surely  they  are  the  two  chief  sources  of  human 
happiness!  Says  Donald  G.  Mitchell:  "Flowers  and  children 
are  of  near  kin.  I  love  to  associate  them,  and  to  win  the  chil- 
dren to  a  love  of  the  flowers."  I  know  of  a  little  lad  to  whom 
the  succession  of  flowers  brings  one  of  the  chief  joys  of  the  year. 
With  what  delight  he  watches  for  each  blossom  in  spring, 
and  how  eagerly  he  tells  of  the  treasure  he  has  found !  Here 
is  a  pleasure  that  is  free  to  all,  and  yet  is  greater  than  any  money 

2 


FLOWERS  AND   HUMANITY 

can  buy.  When  it  is  remembered  that  in  many  cities  there  are 
children  who  have  never  seen  a  buttercup,  the  value  of  main- 
taining flower-gardens  in  city  squares  and  in  every  available 
spot  cannot  be  overestimated.  Let  us  hope  that  the  time  will 
speedily  come  when  every  child,  both  at  home  and  by  means 
of  the  school -garden,  will  be  taught  the  fundamental  facts  of 
plant  life,  not  alone  for  the  practical  advantages  to  be  gained, 
great  as  these  are,  but  that  they  may  have  through  life  a  never- 
failing  resource,  in  the  pursuit  of  which  they  can  always  find 
happiness  and  contentment. 

But  great  as  is  the  pleasure  that  flowers  bestow,  it  is  far  from 
being  the  only  benefit  received  from  them.  It  has  been  rightly 
said  that  "nothing  teaches  us  so  much  in  this  world  as  flowers, 
if  we  will  only  watch  them,  understand  the  messages  they  ex- 
hale, and  profit  by  them.  Every  lesson  in  life  is  taught  by  the 
flowers;  every  message  to  the  human  heart  is  carried  in  them." 
Nor  is  the  time  devoted  by  the  professional  or  laboring  man  to 
the  investigation  of  flowers  wasted,  even  from  a  practical  point 
of  view.  Charles  Kingsley  has  forcibly  described  the  helpful- 
ness of  such  studies: 

"I  know  of  few  studies  to  compare  with  natural  history;  with  the 
search  for  the  most  beautiful  and  curious  productions  of  nature  amid 
her  loveliest  scenery,  and  in  her  freshest  atmosphere.  I  have  known 
again  and  again  working  men  who,  in  the  midst  of  smoky  cities,  have 
kept  their  bodies,  their  minds,  and  their  hearts  healthy  and  pure  by 
going  out  into  the  country  at  odd  hours  and  making  collections  of 
fossils,  plants,  insects,  birds,  or  some  other  objects  of  natural  history; 
and  I  doubt  not  that  such  will  be  the  case  with  some  of  my  readers." 

"Supposing  that  any  of  you,  learning  a  little  sound  natural  history, 
should  abide  here  in  Britain  to  your  life's  end,  and  observe  nothing 
but  the  hedgerow  plants:  he  would  find  that  there  is  much  more  to 
be  seen  in  those  mere  hedgerow  plants  than  he  fancies  now.  .  .  . 
Suppose  that  he  learned  something  of  this,  but  nothing  of  aught  else. 
Would  he  have  gained  no  solid  wisdom  .f^     He  would  be  a  stupider 

3 


THE   FLOWER  AND   THE   BEE 

man  than  I  have  a  right  to  beHeve  any  of  my  readers  to  be,  if  he 
had  not  gained  thereby  somewhat  of  the  most  valuable  of  treasures, 
namely,  that  inductive  habit  of  mind — that  power  of  judging  fairly 
of  facts,  without  which  no  good  or  lasting  work  will  be  done,  whether 
in  physical  science,  in  politics,  in  philosophy,  in  philology,  or  in 
history." 

"Take  my  advice  for  yourselves,  dear  readers,  and  for  your  chil- 
dren after  you;  for,  believe  me,  I  am  showing  you  the  way  to  true 
and  useful,  and,  therefore,  to  just  and  deserved  power.  I  am  show- 
ing you  the  way  to  become  members  of  what  I  trust  will  be — what  I 
am  sure  ought  to  be — the  aristocracy  of  the  future." 

Many  farmers  and  fruit-growers  too  readily  assume  that 
a  knowledge  of  the  life  histories  of  flowers  can  never  aid  them 
in  getting  a  better  livelihood.  There  could  be  no  greater  mis- 
take. The  larger  part  of  our  cultivated  fruits  are  either  par- 
tially or  wholly  self-sterile,  and  in  the  absence  of  bees  and 
other  pollinating  insects  remain  either  entirely  barren  or  largely 
unproductive.  Fruit-culture  on  the  extensive  scale  in  practice 
at  the  present  time  would  be  impossible  without  the  domestic 
bee;  and  it  is  estimated  by  Phillips  that  bee-keeping  annually 
adds  indirectly  more  to  the  resources  of  the  country  by  flower- 
pollination  than  by  the  sale  of  honey  and  wax.  In  sections 
where  immense  orchards  cover  many  square  miles  of  territory, 
the  wild  insects  are  wholly  inadequate  to  pollinate  the  great 
expanse  of  bloom,  and  numerous  apiaries  must  be  maintained 
to  obtain  the  best  results.  An  intimate  knowledge  of  the  way 
fruits  and  vegetables  are  pollinated  is,  therefore,  of  inestimable 
value  to  the  agriculturist. 

To  the  bee-keeper  also  familiarity  with  the  honey  flora  is 
indispensable,  and  may  determine  the  failure  or  success  of  his 
efforts.  Nectar-bearing  plants  may  be  abundant  in  one  local- 
ity, and  comparatively  rare  a  few  miles  away.  Too  often  if 
there  is  a  small  surplus  of  honey,  he  does  not  know  whether  the 

4 


FLOWERS   AND   HUMANITY 

fault  is  with  the  bees  or  with  the  honey  flora.     Unfortunately, 
to  many  an  apiarist  the  wild  flowers  always  remain  strangers. 

"Primroses  by  the  river's  brim 
Dicotyledons  are  to  him, 
And  they  are  nothing  more." 

Then,  again,  there  are  some  bee-keepers  who  appear  to  look 
upon  flowers  as  created  or  evolved  solely  for  the  benefit  of  bee- 
culture.  They  are  slow  to  realize  that  there  are  blossoms 
which  are  nectarless,  or  which  contain  nectar  which  is  inaccessi- 
ble to  honey-bees.  Accordingly  we  find  from  time  to  time, 
bird-flowers,  bumblebee-flowers,  butterfly-flowers,  and  moth- 
flowers,  pollen-flowers,  and  wind-pollinated  flowers  reported  as 
excellent  honey  plants.  That  a  flower  should  produce  nectar 
plentifully,  but  at  the  bottom  of  a  tube  so  long  that  honey-bees 
cannot  reach  it,  seems  to  them  an  evidence,  as  a  Yankee  once 
remarked,  that  "Providence  was  kind,  but  careless."  Nature 
fashioned  the  wild  flowers  before  the  human  race  appeared 
upon  the  earth,  and  they  would  not  have  been  one  whit  different 
to-day  had  the  appearance  of  mankind  been  deferred  to  some 
distant  future. 

Undoubtedly  the  influence  of  flowers  upon  the  development 
of  the  human  race  has  been  both  profound  and  far-reaching. 
So  intimately  do  they  enter  into  every  phase  of  life,  and  so  elo- 
quently do  they  express  every  emotion,  that  it  was  long  believed 
that  their  bright  colors,  sweet  odors,  and  varied  forms  were 
created  solely  for  the  benefit  of  man.  We  cannot  imagine  what 
this  world  would  have  been  without  them,  or  estimate  the  en- 
joyment that  would  have  been  lost,  or  the  power  for  good  that 
would  have  been  forever  missing;  but  we  know  that  humanity 
would  have  been  less  perfect  than  it  is  to-day.  And  the  loss 
of  conspicuous  flowers  is  not  inconceivable,  for  their  develop- 


THE   FLOWER  AND   THE   BEE 

ment  is  correlated  with  insect  visits,  and  in  their  absence  our 
flora  would  have  been  composed  chiefly  of  small,  green  or  dull- 
colored  blossoms,  similar  to  those  of  the  grasses  and  sedges 
and  of  thousands  of  other  plants,  which  are  wind-pollinated, 
and  are  usually  passed  by  almost  unnoticed. 

That  flowers  act  strongly  upon  the  imagination  is  shown 
by  the  myths  of  the  Greeks,  and  the  poetry  of  all  nations. 
Even  the  ruder  songs  of  the  primitive  northern  nations,  accord- 
ing to  Humboldt,  were  influenced  by  the  forms  of  plants. 
Of  the  relations  of  flowers  to  humanity,  the  poet  is  the  true 
interpreter,  not  the  man  of  science.  He  alone,  as  Longfellow 
has  said,  is  qualified  to  unfold  the  bright  and  glorious  revela- 
tions and  the  wondrous  and  manifold  truths  written  in  these 
stars  of  earth. 

"And  the  poet,  faithful  and  far-seeing. 
Sees,  alike  in  stars  and  flowers,  a  part 
Of  the  selfsame  universal  being 

Which  is  throbbing  in  his  brain  and  heart. 

Brilliant  hopes,  all  woven  in  gorgeous  tissues, 

Flaunting  gaily  in  the  light; 
Large  desires,  with  most  uncertain  issues. 

Tender  wishes  blossoming  at  night. 

These  in  flowers  and  men  are  more  than  seeming; 

Workings  are  they  of  the  selfsame  powers 
Which  the  poet  in  no  idle  dreaming 

Seeth  in  himself  and  in  the  flowers. 

In  all  places,  then,  and  in  all  seasons, 

Flowers  expand  their  light  and  soul-like  wings. 

Teaching  us  by  most  persuasive  reasons 
How  akin  they  are  to  human  things." 

While  an  examination  of  the  poetry  which  has  been  written 
on  flowers  in  all  ages  would  teach  many  valuable  lessons,  we 

6 


FLOWERS    AND    HUMANITY 

must  be  content  to  quote  three  verses  from  Leigh  Hunt's 
"Songs  of  the  Flowers,"  in  which  he  surpasses  all  other  poets 
in  his  description  of  the  life  of  flowers  and  their  relation  to  hu- 
manity. From  the  point  of  view  of  the  naturalist  this  is  the 
most  remarkable  poem  on  flowers  in  any  language,  "fathoming,'* 
says  Hamilton  W.  Mabie,  "the  very  soul  of  flowers."  "No 
poet  in  this  nor  in  many  a  generation  past  has  said  a  sweeter 
or  more  haunting  word  for  the  flowers." 

"  We  are  the  sweet  flowers. 

Born  of  sunny  showers, 
Think,  whene'er  you  see  us,  what  })eauty  saith: 

Utterance  mute  and  bright 

Of  some  unknown  delight, 
We  fill  the  air  with  pleasure,  by  our  simple  ])reath: 

All  who  see  us,  love  us; 

We  befit  all  places; 
Unto  sorrow  we  give  smiles;    and  unto  graces,  graces. 

See,  and  scorn  all  duller 

Taste,  how  Heav'n  color  lover. 
How  great  Nature,  clearly  joys  in  red  and  green; 

What  sweet  thoughts  she  thinks 

Of  violets  and  pinks. 
And  a  thousand  flashing  hues  made  solely  to  ])e  seen; 

See  her  whitest  lilies 

Chill  the  silver  showers. 
And  what  red  mouth  has  her  rose,  the  woman  of  the  flowers. 

Think  of  all  these  treasures. 

Matchless  works  and  pleasures. 
Everyone  a  marvel,  more  than  thought  can  say; 

Then  think  in  what  bright  show'rs 

We  thicken  fields  and  bowers, 
And  with  what  heaps  of  sweetness  half  wanton  May. 

Think  of  the  mossy  forest 

By  the  bee-birds  haunted. 
And  all  those  Amazonian  plains,  lone  lying  as  enchanted." 


CHAPTER  II 
THE   DISCOVERY  OF  THE   SECRET  OF  FLOWERS 

THE  human  race  has  long  assumed  (being  the  only  organ- 
ism at  liberty  to  place  upon  itself  its  own  valuation)  that 
it  occupies  a  position  of  fictitious  importance  in  the  uni- 
verse. It  was  a  current  maxim  in  the  Middle  Ages  that  man 
was  the  measure  of  all  things.  The  world  and  its  inhabitants, 
so  ran  this  pleasant  myth,  was  created  a  few  thousand  years 
ago,  solely  to  provide  him  with  a  congenial  place  of  abode; 
and,  because  of  his  paramount  importance,  was  placed  in  the 
centre  of  the  heavens.  Not  a  little  ingenious  (and  to-day 
amusing)  speculation  was  expended  in  an  effort  to  explain  how 
natural  cataclasms  and  noxious  animals  and  plants  were  dis- 
guised blessings ;  but  that  such  was  the  fact,  no  doubt  was  per- 
mitted to  exist.  From  these  modest  pretensions  we  have  been 
receding  for  some  centuries  with  much  hesitation  and  reluctance. 
Perhaps  the  close  of  another  hundred  years  will  see  them  aban- 
doned altogether,  and  humanity  willing  to  admit  that  it  is  a 
part  of  nature,  not  outside  and  above  her. 

So  long  as  these  teachings  prevailed  it  was  very  naturally  a 
popular  notion  that  the  bright  colors  of  flowers  were  of  no 
importance  except  as  they  gave  human  pleasure.  Much  super- 
fluous pity  was  wasted  on  those  blossoms  which,  to  use  the 
words  of  the  poet  Gray,  blushed  unseen  and  wasted  their  sweet- 
ness on  the  desert  air.  Only  a  few  years  ago  a  similar  senti- 
ment was  expressed  by  the  editor  of  one  of  our  popular  maga- 
zines: "There  was  apparently  no  particular  reason  why  the 
earth,  at  the  time  of  Adam,  should  have  been  literally  strewn 

8 


THE   SECRET   OF   FLOWERS 

with  blossoms.     They  were  of  no  particular  use;  there  was  only 
one  man  to  see  them." 

This  same  idea  is  again  repeated  in  Emerson's  beautiful 
lines : 

THE   RHODORA 

"In  May,  when  sea-winds  pierced  our  solitudes 
I  found  the  fresh  rhodora  in  the  woods. 
Spreading  its  leafless  blooms  in  a  damp  nook; 
To  please  the  desert  and  the  sluggish  brook: 
The  purple  petals  fallen  in  the  pool, 
Made  the  black  waters  with  their  beauty  gay: 
Here  might  the  red-bird  come  his  plumes  to  cool. 
And  court  the  flower  that  cheapens  his  array. 
Rhodora!  if  the  sages  ask  thee  why 
This  charm  is  wasted  on  the  marsh  and  sky. 
Dear,  tell  them  that,  if  eyes  were  made  for  seeing. 
Then  beauty  is  its  own  excuse  for  being." 

It  would  seem  never  to  have  occurred  to  poet,  editor,  or 
philosopher  that  the  beautiful  hues  of  flowers  might  be  useful 
to  the  plants  producing  them. 

It  was  a  German  pastor,  Christian  Conrad  Sprengel,  at  the 
close  of  the  eighteenth  century,  who  first  pointed  out  the  true 
significance  of  conspicuous  flowers.  His  book,  now  a  botanical 
classic,  attracted  but  little  attention;  his  publisher  did  not 
even  send  him  a  copy  of  it,  and  in  discouragement  he  did  not 
publish  the  second  volume,  but  turned  from  the  study  of  plants 
to  that  of  languages.  The  title  of  the  work,  The  Secret  of 
Nature  in  the  Form  and  Fertilization  of  Flowers  Discovered, 
affords  us  the  pleasure  of  knowing  that  he  rightly  estimated 
the  importance  of  his  observations.  Sprengel  clearly  states, 
as  is  now  well  established,  that  the  bright  hues  of  flowers  serve 
as  signals  to  attract  the  attention  of  nectar-loving  insects  fly- 
ing near  by.     He  was  led  to  this  conclusion  very  fitly  by  the 

9 


THE  FLOWER  AND   THE  BEE 

study  of  Myosotis,  or  the  forget-me-not.  He  has  not  been 
forgotten.  His  name  and  theory  were  rescued  from  obscurity 
by  Darwin;  his  book  a  few  years  ago  was  repubhshed  at  Leip- 
sic,  and  is  now  universally  recognized,  says  Mueller,  as  having 
"struck  out  a  new  path  in  botanical  science." 

Sprengel  was  convinced  that  the  wise  Framer  of  nature  had 
not  produced  a  single  hair  without  a  definite  purpose,  and  he 
examined  a  great  many  flowers  for  the  purpose  of  learning  the 
meaning  of  their  forms  and  the  arrangement  of  their  parts. 
The  salver-formed  flower  of  the  forget-me-not  is  sky-blue  with 
a  yellow  eye.  "Wliile  studying  the  flower  of  Myosotis  I  was 
struck,"  he  says,  "by  the  yellow  ring  w^hich  surrounds  the 
opening  of  the  corolla  tube,  and  which  is  beautifully  conspicu- 
ous against  the  sky-blue  of  the  limb."  (Fig.  1.)  *' Might  not, 
I  thought,  this  circumstance  also  have  some  reference  to  in- 
sects? Might  not  nature  have  especially  colored  this  ring, 
to  the  end  that  it  might  show  insects  the  way  to  the  nectar- 
reservoir  .^^ "  On  further  observation  he  found  that  the  en- 
trances to  many  other  flowers  w^ere  marked  w^ith  spots,  lines, 
and  dots  differently  colored  from  the  rest  of  the  corolla.  These 
marks  he  called  "nectar  guides."  "If  the  particular  color 
of  one  part  of  a  flower,"  he  rightly  inferred,  "serves  to  enable 
an  insect,  w^hich  has  settled  on  the  flower,  easily  to  find  the 
right  way  to  the  nectar,  then  the  general  color  of  the  corolla  is 
serviceable  in  rendering  the  flowers  provided  with  it  conspicu- 
ous even  from  afar  to  the  eyes  of  insects  that  hover  around 
in  the  air  in  search  of  food." 

Sprengel  decided  that  flowers  secrete  nectar  for  the  sake  of 
attracting  insects,  and  that  it  is  protected  by  hairs  or  nectaries 
in  order  that  they  may  enjoy  it  pure  and  unspoiled.  At  first 
he  thought  that  the  flowers  received  no  service  in  return;  but 
he  soon  observed  that  the  guests  pollinated  the  flowers.     He 

10 


H 

^1 

^^^^^B'    '^^^^yi 

^^^^r           ^  '^^^^^^^^^^^^1 

^^H 

^^^^B            '\:W 

^H 

^^^^^^^^^K    ~            '^'r',"  '9H 

^^^^^^H 

^VPlH^ 

^^H 

WB^^^  i?F^ 

*  ^t^M^^^^i^Wj „ 

3 

^^^          >r^^H 

k  t  ^^^IBRV 

^^H 

^^N^ 

B 1        i^^^^^^H 

fefl 

^^^M 

l&^^^HH 

^^^1 

^^^^^^^^^■k 

Brjjl^^j^^^^^^       n  iiti  1^ 

^^^^^^^^^1 

%      ^ff'"  '''"'-^    1IIMB Illj 

^H 

1  f.J^^B 

^^H 

r'n    '^^'  W    ^^^^^1 

HI 

|H    ^^^       ^^^^B 

^^^^ 

I  ft'^^ 

,^ 

Fig.  1.     Forget-Me-Not.     Myosotis  scorpioides 
Blue  flower  with  yellow  eye 


THE  FLOWER  AND   THE   BEE 

even  noticed  the  frequent  occurrence  of  cross-pollination,  and 
remarks  that  "it  seems  that  nature  is  unwilling  that  any 
flower  should  be  fertilized  by  its  own  pollen."  He  described 
the  manner  in  which  some  five  hundred  flowers  are  pollinated; 
but  as  he  knew  little  about  insects  he  did  not  pay  much  atten- 
tion to  the  different  kinds  of  visitors. 

But  while  Sprengel  had  learned  the  secret  of  flowers  and  knew 
that  their  colors,  odors,  and  forms  were  not  useless  characters, 
he  failed  to  discover  why  cross-pollination  is  beneficial;  and 
this  omission,  as  Mueller  has  remarked,  was  for  several  genera- 
tions fatal  to  his  work.  In  1841  Robert  Brown,  an  eccentric 
English  botanist  of  great  learning,  advised  Darwin  to  read 
Sprengel's  book.  *'It  may  be  doubted,"  says  Francis  Darwin, 
"whether  Robert  Brown  ever  planted  a  more  beautiful  seed 
than  putting  such  a  book  into  such  hands."  Thus  is  the  torch 
of  learning,  shining  with  ever-increasing  effulgence,  handed  on 
from  one  investigator  to  another.  Darwin  was  already  en- 
gaged in  studying  British  orchids,  of  which  he  wrote  to  Ben- 
tham:  "They  are  wonderful  creatures,  these  orchids."  His 
interest  in  the  structure  and  pollination  of  these  curious  plants 
was  greatly  increased  by  reading  what  the  old  German  pastor 
had  done.  Darwin  soon  discovered  that  frequent  crosses  in- 
crease both  the  vigor  and  productiveness  of  the  stock,  and 
that  an  occasional  cross  is  indispensable.  The  principal  agents 
which  nature  employs  for  this  purpose  are  insects,  birds,  wind, 
and  water.  So  impressed  was  Darwin  with  the  importance  of 
cross-fertilization  that  he  closed  his  famous  book  on  orchids, 
which  marks  the  next  great  epoch  in  flower  ecology,  with  the 
words:  "Nature  abhors  perpetual  self-fertilization."  "The 
charm,"  says  Mueller,  "was  now  broken,  and  the  value  of 
Sprengel's  work  was  at  once  recognized."  "The  merits  of  poor 
old  Sprengel,"   says  Darwin  in  his  autobiography,   "so  long 

12 


THE   SECRET   OF   FLOWERS 

overlooked,  are  now  fully  recognized  many  years  after  his 
death." 

In  1866  Darwin's  Origm  of  Speciefi  and  his  book  on  orchids 
were  read  by  Hermann  Mueller,  a  young  teacher  at  Lippstadt, 
Germany,  who  thenceforth  enthusiastically  devoted  the  rest 
of  his  life  to  the  study  of  the  pollination  of  flowers.  Many 
other  investigators  were  also  stimulated  by  these  epoch-making 
books  to  study  the  charming  problems  of  floral  structure,  as 
Delpino  in  Italy,  Axel  in  Sweden,  Hildebrand  in  Germany,  Asa 
Gray  in  North  America,  and  Fritz  Mueller  in  South  America. 
But  they  were  all  easily  surpassed  by  Hermann  Mueller,  who 
is  still  regarded  as  the  foremost  of  floroecologists.  In  Thu- 
ringia  and  in  the  Alps  he  examined  many  hundreds  of  blossoms 
and  recorded  the  visits  of  insects  by  thousands.  He  was  the 
first  to  collect  and  publish  lists  of  flower-pollinators  on  an  ex- 
tensive scale,  and  the  biology  of  flowers  may  thus  be  said  in  its 
broadest  sense  to  have  been  established  by  him.  Never  since 
has  this  branch  of  botany  been  cultivated  with  equal  success. 
His  book  The  Fertilization  of  Flowers  ranks  with  the  works 
of  Sprengel  and  Darwin,  and  marks  the  third  great  epoch  in 
the  history  of  flower  ecology.     (Fig.  2.) 

Hermann  and  Fritz  Mueller  were  the  sons  of  the  Evangelical 
pastor  at  Muhlberg,  in  Thuringia.  Fritz  was  born  in  IS'^^  and 
Hermann  in  1829.  Hermann  was  deeply  attached  to  his  native 
land,  and  often  in  his  later  life  referred  to  it  as  "his  dear  Thu- 
ringia." There  with  Fritz  he  explored  the  fields  and  streams, 
and  under  the  influence  of  his  studious  elder  brother  his  love 
for  the  plant  world  was  awakened. 

After  preparing  himself  for  a  teacher  and  also  studying 
medicine  Fritz  emigrated  to  Brazil,  where  he  settled  at  Blu- 
menau  as  a  farmer.  Afterward  he  went  to  the  Lyceum  at 
Desterro,  but,  on  being  driven  from  office  by  the  Jesuits,  he 

13 


THE   FLOWER   AND   THE   BEE 

returned  to  Blumenau  and  became  travelling  naturalist  for 
the  province  of  Santa  Catharina.  From  his  new  home  he 
rendered  invaluable  service  to  his  fatherland  by  frequently 
communicating  the  results  of  his  scientific  researches  and  im- 
portant observations.  After  his  brother  Hermann's  death  he 
wrote:  "With  Hermann  I  have  during  the  last  twenty  years 
exchanged  one  letter  regularly  each  month,  nor  did  either  of 
us  wait  for  the  answer  to  our  last  letter  before  writing  again." 
By  this  lively  exchange  of  ideas,  which  related  chiefly  to  their 
investigations  in  natural  history,  each  incited  the  other  to 
greater  efforts.  On  the  expulsion  of  the  Emperor  Dom  Pedro, 
Fritz  was  deprived  of  his  office  and  pay  without  explanation, 
and  letters  were  often  not  delivered  to  his  address.  During  a 
battle  near  Blumenau  the  revolutionists  robbed  him  of  a  part 
of  his  property,  imprisoned  him  for  eight  days,  and  he  escaped 
with  his  life  only  by  a  fortunate  accident.  He  died  in  1897; 
his  best-known  work  was  Fur  Darwin,  or  Facts  for  Darwin. 
Two  of  his  grandsons  inherit  his  love  for  nature. 

The  younger  brother,  Hermann,  graduated  from  the  gymna- 
sium at  Erfurt  in  1847.  During  his  spare  time  he  found 
youthful  employment  in  studying  the  floral  wealth  in  the 
environs  of  that  city.  At  the  University  of  Halle,  and  later  at 
Berlin,  geology  became  his  favorite  pursuit.  Two  journeys  to 
the  Alps  awakened  in  him  an  appreciation  of  the  rich  flora  and 
fauna  of  these  mountains.  In  1855  he  became  teacher  in  the 
newly  established  Realschule  in  Lippstadt,  and  ten  years  later 
he  was  appointed  uppermaster,  a  position  he  retained  until  the 
close  of  his  life.  His  first  book.  The  Fertilization  of  Flowers, 
won  the  praise  of  Charles  Darwin  and  has  had  a  world-wide 
usefulness  as  a  work  of  reference  on  flower-pollination.  It  is 
illustrated  by  many  excellent  woodcuts,  the  drawings  for  which 
were  made  by  Mueller  himself.     It  contains  descriptions  of 

14 


THE   SECRET   OF   FLOWERS 

the  floral  mechanisms  of  many  plant  species,  with  lists  of 
their  insect  visitors.  It  will  give  some  idea  of  the  immense 
amount   of   labor   involved   in   its   preparation   to   state   that 


Fig.  2.     Hermann  Mueller 


5,231  visits  to  flowers  by  843  different  kinds  of  anthophilous, 
or  flower-visiting,  insects  are  recorded. 

Mueller  had  never  forgotten  his  earlier  delightful  journeys 
among  the  Alps  nor  its  rich  and  brilliantly  colored  flora.  For 
six  summers  he  continued  with  great  diligence  to  investigate 
its  flowers,  and  the  result  was  his  second  great  work,  entitled 

15 


THE   FLOWER  AND   THE   BEE 

Alpenblumen,  or  the  Flowers  of  the  Alps.  Here  are  enumer- 
ated 5,711  visits  by  841  species  of  anthophilous  insects.  It  is 
impossible  to  read  this  account  of  the  mysteries  of  the  floral 
world  in  high  altitudes  without  longing  to  visit  the  scene  of 
his  investigations.  The  short  summers,  the  rapid  (not  to  say 
impetuous)  advance  of  vegetation,  the  simultaneous  blooming 
of  many  species,  the  brilliant  hues,  the  wealth  of  insects,  and 
especially  the  great  abundance  of  butterflies,  against  a  back- 
ground of  snowy  summits,  form  a  most  enticing  picture. 
Mueller  published  a  third  book  on  flowers,  besides  many  shorter 
papers. 

Hermann  died  very  suddenly,  in  1883,  while  studying  the 
flowers  of  the  Tyrol.  He  was  travelling  in  part  for  the  benefit 
of  his  health,  but  he  was  without  any  premonition  of  his  fate. 
On  the  day  of  his  death  he  had  written  a  long  letter  to  his  son 
at  Lippstadt,  and  his  valise  was  packed  for  his  departure  the 
next  morning.  Suddenly,  on  the  evening  of  the  '25th  of  August, 
a  pulmonary  attack  closed  his  useful  life.  It  was  fitting  that 
a  life  devoted  to  the  study  of  highland  flowers  should  come  to 
its  close  among  them.  "He  is  not  dead,"  says  his  biographer, 
Ludwig;  "he  lives,  and  will  live  so  long  as  a  flower  enraptures 
the  eye  of  an  investigator.  His  bright  spirit  will  live  and,  we 
hope,  like  that  of  his  teacher  and  friend  Darwin,  long  be  a 
light  on  the  way  to  truth  in  the  heart  of  nature." 

Since  Mueller's  death  the  most  important  undertaking  has 
been  Knuth's  Handbook  of  Flower  Pollination,  an  encyclo- 
paedic work  in  three  volumes,  giving  a  complete  summary 
with  a  bibliography  of  some  four  thousand  titles  of  everything 
that  has  been  done  in  floroecology  up  to  the  beginning  of  the 
present  century.  It  was  planned  and  the  first  two  volumes 
brought  out  by  Paul  Knuth,  and  after  his  untimely  death,  at 
forty  years  of  age,  the  third  volume  was  completed  by  Ernst 

16 


THE   SECRET   OF   FLOWERS 

Loew,  of  Berlin.  An  excellent  translation  by  J.  Ainsworth 
Davis  of  the  first  and  second  volumes  has  appeared. 

To-day  there  are  very  few  investigators  engaged  in  studying 
the  life  histories  of  flowers.  In  North  America  they  number 
less  than  half  a  dozen.  Most  observers  are  content  to  restrict 
their  attention  to  the  botanical  side  of  the  subject,  and  ignore 
the  great  company  of  pollinators.  Even  Charles  Darwin  and 
Anton  Kerner,  whose  writings  still  remain  an  ever-inspiring 
source  of  information,  gave  little  heed  to  the  ways  of  the  insect 
guests.  The  reason  for  this  is  not  far  to  seek.  To  collect 
and  prepare  lists  of  the  visitors,  and  to  observe  their  behavior, 
requires  so  enormous  an  amount  of  time,  labor,  and  patience 
that  the  opportunity  is  possible  to  very  few  people.  Suppose 
that  a  flower  is  in  bloom  for  two  weeks,  then,  on  every  calm, 
bright  day  many  hours  must  be  devoted  to  the  work,  for  the 
guests  at  the  beginning  of  blooming-time  may  differ  from  those 
at  its  close.  There  follows  the  almost  insuperable  task,  at 
least  in  America,  of  determining  the  names  of  the  captured 
insects.  With  the  exception  of  the  butterflies  we  have  no 
manuals  of  the  different  orders,  and  the  literature  is  in  a  truly 
chaotic  condition,  many  papers  not  being  obtainable  at  any 
price.  It  is  noteworthy  that  each  of  the  three  or  four  more 
prominent  investigators  of  floroecology  in  America  has  been 
compelled  to  work  up  the  classification  of  the  bees  in  his  lo- 
cality— a  rather  formidable  undertaking  in  itself.  So  closely 
allied  are  the  species  and  genera  that  no  one  can  distinguish 
between  them  without  a  special  knowledge  of  the  group,  which 
in  its  relations  to  flowers  exceeds  all  others  in  importance. 

But  the  value  of  an  acquaintance  with  the  insect  visitors 
cannot  easily  be  overestimated;  for  some  species  fly  only  in 
the  spring,  others  only  in  the  fall;  some  species  visit  only 
one  kind  of  flower,  others  many  kinds;   some  are  most  welcome 

17 


THE   FLOWER  AND   THE  BEE 

guests,  others  are  mere  robbers.  I  should  never  have  dreamed 
that  the  pretty,  nodding  pink  blossoms  of  the  twinflower 
{LinncBa  horealis),  with  its  sweet  vanilla-like  fragrance,  are  in 


Fig.  3.     Bladderwort.     Utncularia  vulgaris 
The  two-lipped  yellow  flowers  are  pollinated  by  syrphid  flies,  both  in  Europe  and  America 

our  northern  woodlands  attractive  to  gnats  alone.  One  after- 
noon a  large  bed  of  these  delicate  flowers  was  carefully  observed, 
and  eight  visitors  were  collected.     On  examination  they  were 

18 


THE   SECRET   OF   FLOWERS 

fouiul  to  ])eloiig  to  a  single  species  of  fly  (Einpis  rufe^cens). 
Further  observations  show  that  in  this  locality  this  fly  is 
probably  the  only  guest.  A  burly  bumblebee  flew  over  the 
flowers  without  ])aying  any  attention  to  them. 

Among  aquatic  plants  living  in  fresh-water  rivers  is  the 
bladderwort  {Utricular la  vulgaris).  The  whole  plant  is  sub- 
merged; but  at  blooming-time  a  flower-stalk  is  thrust  out  of 
the  water,  which  produces  deeply  two-lipped,  bright  yellow 
flowers.  (Fig.  3.)  I  certainly  expected  to  find  it  a  favorite 
of  bees.  But  after  repeated  observations  I  have  collected  on 
the  flowers  in  Maine  only  the  long-tongued  syrphid  fly  {Helo- 
philus  conostomus) .  There  is  no  way  in  which  we  can  so 
easily  learn  the  defects  of  flowers  as  to  watch  the  behavior  of 
insects  upon  them.  No  human  eye  can  discover  them  so 
quickly.  In  a  word,  if  we  would  fully  understand  the  bright- 
hued  floral  edifices  which  so  freely  adorn  the  outdoor  world  we 
must  study  the  modus  operandi  of  their  arcliitects  and  builders. 


19 


CHAPTER   III 

FLOWERS   POIXINATED   BY   THE   WIND 

"Let  us  have  eyes  to  see 
The  new-old  miracle; 
If  it  befell 
We  viewed  for  the  first  time  such  wizardry. 
Each  budding  leaf  were  past  belief. 
Ineffable." 

EARLY  spring  in  temperate  North  America  has  its  own 
peculiar  charm.  It  is  a  period  of  conflict  betw^een  two 
seasons,  ushered  in  by  shrill  winds  and  rushing  waters. 
Snow  and  ice  still  linger  in  the  woods  and  cold  days  and  frosty 
nights  are  common;  but  warmth  and  light  are  continually 
gaining.  Among  the  many  events  characteristic  of  that  old  but 
ever  new  miracle,  the  resurrection  of  plant  life,  the  most  note- 
worthy is  the  bursting  into  bloom  suddenly  in  early  spring  of 
whole  forests  of  deciduous-leaved  trees  and  shrubs  before  their 
leaves  have  appeared.  Many  of  them  are  familiar  species  as 
the  alders,  birches,  poplars,  hazels,  wiilow^s,  hornbeams,  walnuts, 
hickories,  beeches,  elms,  oaks,  and  chestnuts.  A  part  ^^roduce 
edible  nuts,  and  a  part  are  planted  as  avenue  or  ornamental 
trees.  Most  people  never  know  that  they  bloom  at  all.  This 
is  partly  because  the  flowers  are  small  and  dull-colored,  and 
partly  because  they  come  at  a  season  of  the  year  when  they 
are  not  expected.  Why  do  the  flowers  expand  before  the  leaves  .^ 
A  few  years  ago  no  one  could  have  answered  this  question. 

When  Louis  Agassiz,  the  famous  naturalist  and  the  founder 
of  the  Agassiz  Museum  at  Cambridge,  and  Alexander  Braun, 
who  afterward  became  a  distinguished  botanist,  were  school- 

20 


FLOWERS   POLLINATED   BY   THE   WIND 

boys  together  at  Carlsruhe,  in  IS'^T,  Braim  in  one  of  his  letters 
sent  his  friend  some  "nuts  to  pick,"  among  which  was  the  ques- 
tion: "Why  do  some  plants  blossom  before  they  put  forth 
leaves?"  Years  before  Gilbert  White,  the  naturalist  of  Sel- 
borne,  had  pondered  over  the  same  problem.  "  Why,"  he  writes, 
"do  some  plants  bloom  in  the  very  first  dawnings  of  spring, 
some  at  midsummer,  and  some  not  till  autumn?  This  cir- 
cumstance is  one  of  the  wonders  of  creation,  little  noticed  be- 
cause a  common  occurrence — but  it  would  be  as  difficult  to  be 
explained  as  the  most  stupendous  phenomena  in  nature." 

Difficult  as  the  problem  once  seemed,  there  is  no  longer 
any  mystery  why  the  flowers  of  many  forest-trees  appear  be- 
fore their  leaves.  They  are  or  were  in  time  past  pollinated  by 
the  wind,  although  the  willows  and  maples  have  in  com- 
paratively recent  years  changed  over  to  insect-pollination. 
At  its  best,  wind-pollination  is  a  very  wasteful  method  of  ob- 
taining the  advantages  of  cross-fertilization,  and  much  of  the 
pollen  falls  where  it  is  of  no  benefit.  It  would  clearly  be  al- 
most a  total  failure  in  the  case  of  the  shrubs  and  trees  enumer- 
ated, if  their  branches  were  covered  with  a  dense  foliage  which 
intercepted  the  pollen.  So  the  flower-buds  are  formed  the 
preceding  season,  and  begin  to  bloom  in  spring  just  as  soon 
as  the  weather  is  warm  enough.  If  Gilbert  White  were  living 
to-day  this  phenomenon  would  excite  his  astonishment  less 
and  his  admiration  more. 

The  common  alder  is  one  of  the  commonest  of  New  England 
shrubs,  growing  everywhere  in  swamps  and  wet  land,  and  it  is 
also  an  excellent  example  of  wind-pollination.  It  blooms  early 
in  April,  and,  where  the  Mayflower  is  not  found,  is  the  true  har- 
binger of  a  new  season.     (Fig.  4.) 

"By  the  flowing  river  the  alder  catkins  swing. 
And  the  sweet  song  sparrow  cries,  'Spring!    it  is  spring.'" 

21 


THE   FLOWER   AND   THE   BEE 

The  flowers  of  the  akier  are  in  catkins  or  ainents.     A  cat- 
kin  is   a  cylindrical   flower-cluster   composed   of   many   small. 


1 

N 

M 

B 

in 

i 

rfl 

Fig.  i.     Common  Alder.     Alnns  incana 
A,  fertile  catkins  ;  B,  staminate  catkins  ;  a  wind-pollinated  shrub 

nearly  sessile  flowers,   and  numerous  protecting  scales.     The 
stamens    and    pistils    are    always    in    different    catkins.     In    a 


FLOWERS  POLLINATED   BY  THE   WIND 

staminate  catkin  of  tlie  aider  I  found  by  actual  count  77  flowers 
and  310  stamens;  while  a  pistillate  catkin  contained  80  pistils. 
A  tassel  of  three  or  four  staminate  catkins  occurs  at  the  end  of 
a  branch,  while  an  inch  or  two  higher  uj),  where  the  pollen 
cannot  fall  upon  them,  are  one  or  two  clusters  of  pistillate  or 
fruiting  catkins.  This  arrangement  facilitates  cross-pollina- 
tion. There  are  no  allurements  to  attract  insects,  such  as  nec- 
tar, bright  color,  odor,  or  resting-places,  for  the  wind  is  the 
agent  which  carries  the  pollen.  On  a  warm,  clear  day  the 
last  of  March  or  early  in  April,  often  before  the  swamps  are 
wholly  free  from  ice,  the  anthers  open  and  weigh  down  the 
passing  breeze  with  little  clouds  of  pollen.  Most  of  the  pollen 
would  be  wasted  if  the  bushes  were  in  full  foliage.  The  honey- 
bees obtain  their  earliest  supply  of  pollen  from  the  alders,  and 
in  northern  New  England  they  are  fortunate  if  their  work  is 
not  interrupted  by  a  snow-storm.  The  seeds  mature  during 
the  summer,  and  the  following  winter  are  dropped  upon  the 
drifting  snow. 

Later  in  April  the  willows  begin  to  bloom,  the  familiar  pussy- 
willow (Salix  discolor)  leading  the  way.  While  no  one  ever 
gathers  the  dark  reddish-brown  catkins  of  the  alder,  the  pussy- 
willows are  very  attractive  and  are  often  sold  in  New  England 
cities  by  street  flower- venders,  and  used  for  decoration  in 
English  churches  on  Palm  Sunday.  The  staminate  and  pis- 
tillate catkins  are  borne  on  different  trees  or  bushes  so  that 
self-pollination  is  impossible.  In  a  staminate  catkin  I  counted 
270  flowers,  and  in  a  pistillate  catkin  14'2  flowers.  The  blos- 
soms are  sweet-scented,  secrete  nectar  freely,  and  on  a  warm 
day  are  sought  by  a  great  company  of  honey-bees,  bumble- 
bees, solitary  bees,  flies,  and  a  few  butterflies  and  beetles,  from 
which  it  is  evident  that  they  are  to-day  pollinated  by  insects. 
But  since  the  flowers  are  in  catkins  and  "bare  are  the  branches, 

23 


THE   FLOWER  AND   THE   BEE 

and  cold  is  the  air"  when  they  bloom,  we  are  safe  in  concluding 
that  earlier  in  their  history  they  were  wind-pollinated;  indeed, 
in  Greenland  anemophilous  willows  are  still  found.  Salix  is  a 
very  old  genus,  and  fossil  willow  leaves  occur  in  the  rocks 
earlier  than  those  of  most  modern  plants.  The  transition  in 
the  manner  of  pollination  has  probably  been  brought  about  by 
bees,  w^hich  visit  the  catkins  in  great  numbers  for  pollen. 

The  willows  are  a  bonanza  to  the  bee-keeper,  for  they  bloom 
at  a  time  when  the  winter  stores  in  the  hives  are  beginning  to 
fail,  and  are  a  great  help  in  tiding  over  our  cold,  inclement 
springs.  They  furnish  the  first  honey  of  the  season,  and  with 
them  begins  the  procession  of  the  honey -plants,  or  plants  valu- 
able in  the  production  of  honey.  A  small  surplus  is  sometimes 
obtained,  which  has  a  pleasant  aromatic  taste  not  unlike  that 
of  fruit-bloom. 

Common  forest  trees  and  shrubs,  which  are  catkin  or  ament- 
bearers  {Amentiferas)  and  are  wind-pollinated,  are  the  poplars, 
birches,  hornbeams,  bayberries,  oaks,  hazels,  sweet-fern,  wal- 
nuts, butternuts,  and  hickories.  The  staminate  and  pistillate 
catkins  of  the  poplars  are  borne  on  different  trees.  When  the 
weather  is  clear  and  dry  the  elastic  anthers  expel  the  pollen 
grains  several  inches  into  the  air,  and  thus  give  them  a  fair 
start  on  their  journey.  The  bayberry  is  also  dioecious.  (Fig. 
5.)  The  white,  yellow,  and  gray  birches  and  the  hornbeams 
are  monoecious,  or  produce  both  kinds  of  catkins  on  the  same 
trees.  (Fig.  6.)  The  staminate  flowers  of  the  oaks,  hazels, 
walnuts,  and  hickories  are  in  long,  drooping  catkins,  but  the 
pistillate  or  fertile  flowers  are  solitary  or  few  in  a  cluster.  The 
beech,  elm,  and  ash  are  likewise  wind-pollinated,  but  none  of 
the  flowers  are  in  catkins.  In  the  beech  the  pistillate  flowers 
are  in  pairs,  and  the  staminate  blossoms  in  globose  heads  which 
droop  downward  on  long,  flexible  stems.     The  flowers  of  the 

24 


Fig.  5.     Bayberry.     Myrica  carolinensis 
A,  fertile  catkins;  B,  sterile  catkins,  producing  only  pollen.     A  wind-pollinated  shrub 


D.   H.   HILL  LlBRAirir 


THE   FLOWER  AND   THE   BEE 

elm  are  largely  lierinai)hrodite  or  perfect,  and  self'-i)ollination 
is  to  a  great  extent  prevented  by  the  stigmas  maturing  earlier 
than  the  anthers.     Both  the  staminate  and  pistillate  flowers 


^^^H^iy^^^^^^^H 

HS'- F^^P^^^^^H^^I 

^^Kyj^^^^^O! 

^^B^^^^^^K^v^H 

Fi(i.  0.     CIray  Birch.     BehiJa  popvlifolia 
A,  fertile  catkin;  B,  staminate  catkin.     A  wind-pollinated  tree 

of  the  ash  are  in  clusters,  and  in  our  species  are  usually  on 
different  trees. 

All  of  these  genera  possess  certain  contrivances  or  adapta- 
tions which  tend  to  prevent  self-pollination  and  to  strongly 
favor  cross-pollination.     The  stamens  and  pistils  are  often  in 

26 


»^f  - 


Fig.  7.     Yellow  Birch.     Betida  Intea 
A,  fertile  catkins;  B,  staminate  catkins.     A  wind-pollinated  tree 


THE   FLOWER   AND   THE   BEE 

different  flowers  and  flower-clusters  either  on  the  same  tree  or 
on  different  trees.  The  fertile  flowers  are  also  higher  up  on 
the  branch  than  the  sterile.  Even  in  the  elm  a  part  of  the 
flowers  are  unisexual.  The  stigmas  are  in  a  receptive  condi- 
tion two  or  three,  or  even  four  or  five,  days  before  the  anthers 
open,  or  sometimes  the  anthers  may  mature  before  the  stigmas. 
The  pistillate  flowers,  whether  solitary  or  in  clusters,  are  nearly 
rigid  and  motionless,  since  it  would  be  of  no  benefit,  if  not  an 
actual  disadvantage,  for  them  to  oscillate  in  the  breeze;  but 
there  is  always  provision  for  shaking  the  anthers.  This  in 
most  instances  is  very  effectively  accomplished  by  the  pendu- 
lous catkin;  but  in  the  beech  the  drooping  head  of  staminate 
flowers  on  a  long  stem  sways  easily  to  and  fro  in  the  wind, 
while  in  the  elm  the  stamens  double  in  length  after  the  flower- 
buds  expand,  so  that  a  slight  air  current  causes  the  anthers  to 
vibrate.  Finally  they  all  produce  a  copious  supply  of  pollen, 
which  must  be  protected  from  too  much  moisture.  The  an- 
thers, therefore,  open  only  when  the  air  is  warm  and  dry,  and 
in  the  event  of  a  sudden  shower  the  fissure  may  close  in  a  few 
seconds.  An  ideal  condition  is  a  clear  day  and  a  gentle  breeze, 
which  prevents  the  pollen  from  falling  too  quickly  to  the  ground 
and  widely  diffuses  it  through  the  atmosphere,  permitting  it  to 
settle  slowly  over  an  extensive  area.  In  a  complete  calm  the 
grains  do  not  fall  out  readily  from  the  anther-cells;  but  a  high 
wind  whirls  them  away  too  forcibly  in  one  direction  and  causes 
excessive  waste. 

Our  northern  hardwood  forests  often  consist  almost  w^holly 
of  birches,  oaks,  beeches,  and  the  other  trees  enumerated, 
which  cover  large  areas  of  land.  There  are  literally  acres  of 
bloom  and  a  numberless  host  of  flowers.  For  the  most  part 
they  are  a  delicate  pale  green,  not  easily  distinguished  from  the 
newly  expanding  leaves;    but  the  catkins  of  the  yellow  birch 


Fig.  8.     American  Elm.     Uhiius  americana 
A  wind-pollinated  tree  with  flowers  in  clusters 


THE   FLOWER  AND   THE  BEE 

are  a  golden  yellow,  and  the  elms  display  great  masses  of  red- 
dish-purple blossoms.     (Figs.  7  and  8.) 

Two  other  immense  groups  of  plants,  which  are  anemophilous 
or  wind-pollinated,  are  the  grasses  (Graminew)  and  the  sedges 
{Cyperaceop).  There  are  some  3,000  species  of  sedges  and  3,500 
species  of  grasses;  but  great  as  is  the  number  of  species,  their 
importance  consists  in  the  myriads  of  individuals  which  cover 
a  large  part  of  the  earth's  surface  and  provide  most  of  the  food 
material  of  the  human  race  and  herbivorous  animals.  To  the 
grasses  belong  the  edible  cereals,  corn,  wheat,  rye,  barley,  oats, 
rice,  and  millet.  "Next  to  the  importance,"  says  Ingalls, 
"of  the  divine  profusion  of  water,  light,  and  air,  those  great 
physical  facts  which  render  existence  possible,  may  be  recorded 
the  universal  beneficence  of  grass.  It  is  the  type  of  our  life, 
the  emblem  of  our  mortality.  It  bears  no  blazonry  of  bloom 
to  charm  the  senses  with  fragrance,  or  splendor,  but  its  homely 
hue  is  more  enchanting  than  the  lily  or  the  rose.  Should  its 
harvest  fail  for  a  single  year,  famine  would  depopulate  the 
earth." 

Most  grasses  have  perfect  or  hermaphrodite  flowers,  and 
self-pollination  is  largely  prevented  by  the  anthers  and  stigmas 
maturing  at  different  times;  but  Indian  corn  is  a  familiar  ex- 
ample of  a  grass  with  unisexual  flowers.  The  spindles  or 
staminate  flower-clusters  terminate  the  stalks  and  are  borne 
well  above  the  foliage,  while  the  pistillate  clusters  (the  ears  in 
the  silk)  stand  much  lower  down,  where  they  are  more  likely  to 
be  cross-pollinated.  A  part  of  the  sedges  have  perfect  flowers 
(Fig.  9),  but  in  a  large  number  of  species  (Care.v)  they  are 
unisexual,  both  fertile  and  sterile  flowers  occurring  in  the  same 
spike  or  flower-cluster,  or  in  different  spikes  on  the  same 
plant  (Fig.  10),  or  more  rarely  on  different  plants.  Self-fertiliza- 
tion is  not  uncommon  in  both  families. 

30 


Fig.  9.     Cotton-Grass.     EripJiorum  virgiyiicum 
A  M'incl-pollinated  sedge 


THE  FLOWER  AND   THE  BEE 

A  few  grasses  bloom  in  the  afternoon,  but  the  majority  open 
in  the  earher  part  of  the  day,  many  at  sunrise  or  a  Httle  later. 
Let  us  go  out  into  the  fields  at  four  o'clock  on  a  morning  early  in 
July.  The  sun  has  not  yet  appeared  above  the  horizon,  but  a 
clear  sky  betokens  a  fair  day.  There  is  hardly  a  breath  of  wind, 
and  so  still  is  the  air  that 

"One  might  well  hear  the  opening  of  a  flower." 

There  is  a  legend  that  in  ancient  Egypt  when  the  first  rays 
of  the  rising  sun  fell  on  the  gigantic  statue  of  Memnon,  of  which 
only  a  shattered  fragment  now  remains,  there  issued  from  it 
a  sound  which  was  believed  to  be  the  voice  of  the  god.  But  it 
is  a  nobler  greeting,  the  actual  culmination  of  their  life  cycle, 
with  which  the  flowering  grasses  welcome  the  great  source  of 
life  and  light. 

The  eastern  sky  has  long  been  tinged  with  red,  and  at  last 
the  sun  appears  above  the  hills  and  its  beams  overflow  the 
world.  With  the  gradually  rising  temperature  the  glumes,  or 
bracts,  which  protect  the  grass-flowers,  separate  and  the  an- 
thers protrude,  pushed  out  by  the  rapidly  lengthening  fila- 
ments, which  grow  several  millimetres  in  a  few  minutes.  At  a 
quarter  before  five  the  stamens,  which  attain  their  full  length 
in  about  fifteen  minutes,  of  the  common  herd's-grass  {Phleum 
pratense)  are  fully  grown.  (Fig.  11.)  The  anthers  are  ver- 
satile or  delicately  hinged  at  their  centres  so  that  they  hang 
perpendicularly  downward.  At  the  lower  end  of  each  anther  a 
narrow  slit  appears,  which  slowly  extends  upward,  the  ends  of 
the  anther  becoming  spoon-shaped  to  prevent  the  too  rapid 
escape  of  the  pollen.  A  slight  breeze  is  stirring.  From  time 
to  time  little  clouds  of  pollen-dust  are  shaken  out,  which  de- 
scend diagonally  to  the  ground,  not  infrequently  without  effect- 
ing pollination.     In  an  hour's  time  nearly  all  the  spikes  had 

32 


Fig.  10.     Fringed  Sedge.     Carex  crinita 
A,  staminate  calkins;  B,  fertile  catkins.     All  the  sedges  are  wind -pollinated 


Fig.  11.     Herd's-Grass.      Phleum  pratense 
A  grass  pollinated  at  sunrise 


Fig.  12.  Quitch-Grass.      Agropyron  repens 
A  grass  pollinated  shortly  after  sunrise 


THE  FLOWER  AND   THE   BEE 

dehisced,  although  there  were  a  few  belated  flowers.  The 
white,  feathery  stigmas  were  as  beautiful  as  frost-crystals. 
Early  as  it  was,  I  found  a  little  syrphid  fly  eating  the  pollen 
from  the  anther  tips ;  evidently  it  had  breakfasted  here  on  many 
previous  mornings. 

Quitch-grass,  or,  as  it  is  popularly  known,  "witch-grass" 
{Agropyron  repens),  is  also  an  early  bloomer  (Fig.  12),  the 
flowers  opening  from  six  to  six-thirty  o'clock,  about  half  an 
hour  later  than  herd's-grass.  While  most  grasses  bloom  before 
noon,  Kerner  gives  a  list  in  which  he  enumerates  a  species  for 
nearly  every  hour  in  the  day.  In  widely  separated  localities 
and  under  different  climatic  conditions  there  would  seem  to 
be  considerable  variation  in  the  hour  of  anthesis.  Long  be- 
fore noon  the  pollen  of  many  field-varieties  has  been  swept  away, 
and  no  change  takes  place  in  the  floral  apparatus  during  the 
remainder  of  the  day.  It  is  from  its  appearance  at  midday 
that  most  persons  judge  of  the  inflorescence  of  the  grasses; 
but  it  is  well  worth  while  to  view  it  early  in  the  morning,  when, 
although  not  gaily  hued,  it  will  be  seen  to  possess  a  delicate 
beauty  of  its  own,  which  will  greatly  surprise  those  who  behold 
it  for  the  first  time. 

In  northeastern  America,  north  of  Tennessee  and  east  of  the 
Rocky  Mountains,  I  place  the  number  of  angiospermous  or 
true  flowers  pollinated  by  the  wind  at  about  one  thousand. 
The  total  number  of  wind-pollinated  species  in  the  world  proba- 
bly exceeds  twelve  thousand.  Besides  the  deciduous-leaved 
forest-trees,  and  the  grasses,  rushes,  and  sedges,  there  are  many 
coarse,  homely  weeds  such  as  the  pigweeds  (Fig.  13),  ragweeds, 
nettles,  hops,  pondweeds,  sorrels,  docks,  plantains,  hemp, 
and  meadow-rue.  They  agree  in  having  small,  inconspicuous 
flowers,  which  are  commonly  odorless  and  nectarless,  but  which 
are   produced   in   immense   numbers.      The   pollen-grains   are 

36 


Fig.  13.     Purple  Amaranth,      Amaranthus  caudatus 
A  wiud-polliuated  annual  herb 


THE   FLOWER  AND   THE   BEE 

round  and  smooth,  while  the  stigmas  are  lobed  or  feathery  to 
present  as  large  a  receptive  surface  as  possible.  They  flourish 
in  a  great  variety  of  situations  and  all  present  interesting 
phenomena  worthy  of  careful  observation.  The  Roman  worm- 
wood (Ambrosia  artemisiifolia)  blooms  in  the  fall  and  is  com- 
mon everywhere  in  old  fields  and  waste  land.  (Fig.  14.)  The 
air  is  filled  with  the  yellow  pollen,  which  is  believed  to  be  pro- 
ductive of  hay-fever.  The  plantains  are  midway  between  wind- 
pollination  and  insect-pollination.  (Fig.  15.)  The  pleasant 
odor  and  nectar  attract  insects,  but  the  smooth  pollen-grains 
are  likewise  carried  by  the  wind.  The  elastic  stamens  of  the 
stinging  nettles  are  in  the  bud,  doubled  back  upon  themselves 
and  held  under  tension.  When  the  flowers  expand  the  fila- 
ments suddenly  straighten  and  little  puffs  of  pollen  are  forcibly 
projected  into  the  air,  appearing  like  minute  explosions. 

THE  EVERGREEN  OR  CONE  TREES 

"Red-cedars  blossom  tu,  though  few  folks  know  it. 
An'  look  all  dipt  in  sunshine  like  a  poet." — Lowell. 

Vast  forests  of  evergreen  or  coniferous  trees,  covering  mil- 
lions of  acres,  are  found  throughout  the  north  temperate  zone 
of  both  the  Old  and  New  Worlds.  Large  portions  of  Canada 
are  densely  forested  with  white  pine  and  black  spruce ;  in  Siberia 
there  are  great  tracts  of  pine,  cedar,  and  larch;  in  Russia  of 
Scotch  fir,  spruce,  and  Siberian  larch;  and  along  the  southern 
shore  of  the  Baltic  of  fir  and  Norway  spruce.  The  aspect 
within  these  northern  forests  of  conifers  is  dark  and  cold ;  there 
is  little  underbrush  and  the  groinid  is  bare  or  carpeted  with 
mosses  and  lichens — "a  solitude  made  more  intense  by  dreary- 
voiced  elements."  Unlike  the  forests  of  the  tropics,  all  kinds 
of  animal  life  are  scarce,  and  no  bright-colored  birds,  butter- 
flies, or  flowers  light  up  these  sombre  solitudes. 

38 


Fig.  14.     Roman  Wormwood.      Ambrosia  artemi.siifolia 


THE   FLOWER  AND   THE   BEE 

Asa  Gray  and  the  older  botanists  often  speak  of  "the  flowers" 
of  the  conifers,  but  the  naked  seeds  and  the  absence  of  a  stigma, 
as  well  as  a  difference  of  opinion  as  to  what  constitutes  a  flower 
and  what  an  inflorescence,  are  objections  to  this  usage.  It  is 
better  to  restrict  the  word  flower  to  the  Angiosperms,  or  plants 
with  the  seeds  in  a  closed  seed-vessel  a  part  of  which  is  special- 
ized to  receive  the  pollen.  The  cone-trees  and  the  tropical, 
fern-like  cycads,  which  are  also  wind-pollinated,  belong  to  the 
Gymnosperms. 

There  are  in  the  world  about  350  species  of  conifers  {Coni- 
ferales),  all  of  which  are  wind-pollinated.  The  cones  are  al- 
ways unisexual,  either  staminate  ("male")  or  ovulate  ("fe- 
male"). Both  kinds  usually  occur  on  the  same  tree,  but  in  the 
juniper  and  yew  they  are  mostly  on  different  trees.  The  fruit- 
ing cones  are  produced  in  positions  where  they  are  likely  to 
be  cross-pollinated;  for  instance,  in  the  fir  and  spruce  they  are 
on  the  apex  of  the  lofty  spire,  while  the  staminate  cones  are 
very  abundant  on  the  lateral  branches. 

When  the  evergreen  forests  bloom  in  May,  "few  folks,"  as 
the  poet  says,  ever  know  it,  for  the  neutral-colored  cones  do 
not  usually  contrast  strongly  with  the  green,  needle-like  leaves ; 
but  there  are  exceptions.  A  red  pine  covered  with  red-purple 
cones,  half  an  inch  in  length  and  associated  in  clusters  of 
thirty  or  more  (Figs.  16  and  17),  and  a  black  spruce  {Picea 
mariana)  and  balsam-fir  bearing  innumerable  staminate  cones 
about  the  size  and  color  of  a  field-strawberry  certainly  present 
a  strikingly  handsome  appearance.  (Figs.  18  and  19.)  The 
fertile  cones  are  much  less  noticeable,  but  they  are  purple  in 
the  spruce  and  pale-green  in  the  fir. 

The  quantity  of  pollen  produced  by  the  coniferous  forests  is 
almost  beyond  belief.  Clouds  of  pollen  rising  from  pine-trees 
are  sometimes  mistaken  for  columns  of  smoke.     The  falling 

40 


Fig.  15.     English  Plantain.      Plantago  lanceolata 

A,  fertile  spikes;  B,  staminate  spikes.     A  plant  midway  between  wind-pollination  and  insect- 
pollination 


Fig.  16.     Red  Pine.     Pinus  resinosa 
Staminate  cones.     A  wind-pollinated  conifer 


Fig.  17.     Red  Pine.     Pimis  resinosa 
Ovulate  cones.     A  wind-pollinated  conifer 


Fig.  18.     Balsam-Fir.     Abies  halsamea 
Staminate  cones.     A  wind-pollinated  conifer 


FLOWERS   POLLINATED   BY   THE   WIND 

of  pollen-grains  in  such  immense  numbers  that  they  tinge  the 
ground  yellow  in  places  has  given  rise  to  the  reports  of  sulphur- 
showers.  In  pine-forests  the  air  is  filled  with  pollen,  which 
slowly  settles  downward,  powdering  the  foliage  and  branches 
of  the  trees,  the  grass,  and  the  ground.     The  wide  dissemina- 


FiG.  19.     Balsam-Fir.     Abies  balsamea 
Ovulate  cones.     A  wind-pollinated  conifer 


tion  of  pine-pollen  is  favored  by  two  bladder-like  wings,  which 
greatly  increases  its  buoyancy.  Where  everything  is  covered 
with  pollen  it  cannot  fail  to  come  directly  in  contact  with  the 
ends  of  the  ovules,  in  each  of  which  there  is  a  small  orifice,  the 
micropyle,  or  little  gate.  This  opening  is  filled  with  a  drop  of 
mucilaginous  liquid,  well  shown  in  the  yew  and  running  juniper, 
to  which  the  pollen  adheres  and  is  subsequently  drawn  into  the 
ovule  by  its  reabsorption.     Coniferous  pollen  is  not  attractive 

45 


THE   FLOWER   AND   THE   BEE 

to  bees,  probably  because  it  is  too  resinous;  but  it  is  not  in- 
frequently eaten  by  beetles. 

In  a  prolonged  calm  the  portion  of  the  pollen  which  falls 
from  the  anthers  is  not  wholly  lost,  but  is  mostly  caught  and 
temporarily  lodged  on  the  backs  of  the  cone-scales  standing 
underneath,  from  which  it  is  later  swept  away  by  the  wind. 
The  scales  of  the  red  pine  are  reflexed  so  that  their  upper  sur- 
faces form  little  trays,  while  those  of  the  common  juniper  are 
bent  backward  into  little  pockets.  These  structures  are  ap- 
parently not  adaptations  but  incidental  results,  for  in  the  fir 
the  apex  of  each  scale  is  bent  downward,  the  base  is  narrow 
and  a  concavity  is  almost  absent.  In  wet  weather,  moreover, 
the  little  pockets  are  apt  to  gather  moisture,  although  this  is 
partly  prevented  by  their  expansion  and  consequent  closure. 

Wind-pollination  is  the  oldest  and  most  primitive  method 
of  pollen  dispersion,  and  for  millions  of  years  the  only  form 
of  pollination  in  existence.  There  were  wind-pollinated  trees 
as  far  back  as  the  Devonian,  and  in  the  Mesozoic  Age  a 
remarkably  equable  climate  prevailed  over  a  large  extent  on 
the  land  surface  of  the  globe  and  gymnospermous  trees  were 
the  dominant  forms  of  plant  life.  There  were  conifers,  cycads, 
maidenhair-trees,  and  cycadophytes  in  the  greatest  variety, 
and  they  were  all  pollinated  by  the  wind.  Insect-pollination 
is  a  comparatively  recent  event.  The  eflBciency  of  anemophily 
is  proven  not  only  by  its  age,  but  also  by  the  fact  that  if  the 
number  of  individuals  is  considered  rather  than  the  number  of 
species,  then  far  more  plants  are  pollinated  to-day  by  wind 
than  by  insects. 


46 


CHAPTER   IV 

BEES  AS   BUILDERS   OF  FLOWERS 

AS  pollinators  of  flowers,  the  bees,  or  Anihophila  (flower- 
/-%  lovers)  far  surpass  all  other  insects  in  importance.  In 
their  adaptations  for  collecting  pollen  and  nectar,  in 
diligence,  and  in  mental  attributes,  bees  stand  easily  in  the 
first  rank.  To  them  more  than  to  any  other  insects  is  due  the 
evolution  of  our  flora.  L'nlike  all  other  flower-visitors  they 
collect  pollen,  and  it  is  this  habit  which  has  gained  them  their 
pre-eminence  in  the  floral  world,  ^he  beetles,  flies,  and  butter- 
flies take  no  thought  for  their  young  except  to  select  a  suitable 
place  in  which  to  lay  their  eggs.  The  solitary  wasps  provision 
their  nests  vd\h  flies,  spiders,  beetles,  and  other  insects,  which 
by  stinging  they  have  left  paralyzed  and  helpless  or  dead; 
while  the  social  wasps  go  a  step  further  and  masticate  their 
prey  before  feeding  it  to  their  young.  But  bees  are  the  only 
insects  which  feed  their  offspring  with  pollen;  they  are  thus 
wholly  dependent  upon  flowers,  both  for  food  for  themselves 
and  their  brood. 

As  the  result  of  this  interdependence  of  bees  and  flowers, 
united  with  the  industry  and  mental  acuteness  of  the  former, 
there  has  been  developed  a  great  company  of  bright-colored 
blossoms,  which  are  especially  adapted  to  their  \^sits,  and  are, 
in  consequence,  called  "bee-flowers."  They  agree  in  having 
the  nectar  deeply  concealed,  where  it  is  inaccessible  to  ants 
and  other  pillagers.  They  are  often  irregular  in  form,  as  in 
the  pea,  bean,  and  snapdragon.  The  object,  so  far  as  it  is  not 
an  incidental  result,  of  these  odd  and  sometimes  bizarre  forms 

47 


THE  FLOWER  AND   THE  BEE 

is  to  compel  the  bee  to  pursue  a  fixed  path  to  the  nectar  so  that 
polHnation  may  be  effected  with  greater  certainty.  Finally 
they  are  more  often  blue  than  any  other  color.  So  dependent 
are  many  flowers  upon  the  visits  of  bees  that,  in  their  absence, 
they  fail  to  produce  seed.  Such  are  the  red  clover,  salvia,  lark- 
spur, and  some  orchids. 

Irregular  or  one-sided  bee-flowers  occur  in  large  numbers  in 
the  violet,  pea,  mint,  and  figwort  families.  The  nectar  is 
usually  not  deeper  than  7  mm.,  and  the  visitors  are  chiefly 
honey-bees,  bumblebees,  and  long-tongued  solitary  bees. 

The  species  of  the  violet  family  consist  chiefly  of  bee-flowers, 
the  general  form  of  which  is  familiar  to  every  one.  One  warm, 
clear  day  in  early  May  I  found  the  round-leaved  yellow  violet 
(Viola  rotundifoUa)  blooming  luxuriantly  beneath  an  old  beech- 
tree.  Bumblebees,  as  well  as  smaller  bees  belonging  to  the 
genera  Nomada  and  Andrena,  were  flitting  busily  about  from 
flower  to  flower.  On  the  other  hand,  our  wild  blue  violets  are 
very  sparingly  visited  by  bees  or  any  insects,  and  are  often 
infertile.  (Fig.  20.)  This  is  doubtless  the  reason  why  many 
species  produce,  besides  their  showy  blossoms,  small  green 
flowers  (cleistogamy  flowers),  which  never  expand  but  are  very 
fruitful. 

The  beautiful  and  richly  variegated  varieties  of  the  pansy 
{Viola  tricolor)  have  been  produced  partly  by  selection  and 
partly  by  hybridization.  The  corolla  may  be  pure  white, 
yellow,  red,  blue,  purple,  or  black,  or  there  may  be  manifold 
combinations  of  these  hues.  (Fig.  21.)  These  striking  diversi- 
ties result  from  various  mixtures  and  modifications  of  two  pig- 
ments contained  in  the  epidermis — violet-colored  sap  and 
yellow  granules.  In  the  pansy  the  spur  at  the  base  of  the 
lower  petal  contains  the  nectar.  The  anthers  lie  close  together, 
forming  a  cone,  into  the  centre  of  which  is  shed  the  dry  pollen; 

48 


BEES  AS   BUILDERS   OF  FLOWERS 

and  directly  in  front  of  this  cone  stands  the  stigma,  on  the  lower 
side  of  which  there  is  a  flexible,  lip-like  projection.  To  reach 
the  nectar  a  bee  must  run  its  tongue  through  the  centre  of  the 


Fig.  20.     Blue  Violet.     Viola  cucvUata 

A  bee-flower;  the  veins  on  the  lower  petal  serve  as  nectar-guides;  the  spur,  or  nectary,  is 
shown  in  the  two  lower  flowers 


cone  of  anthers;  and  when  it  is  withdrawn  the  grains  of  pollen 
cling  to  its  moistened  surface,  while  the  lip  of  the  stigma  bends 
it  away  so  that  self-pollination  is  prevented.  But  when  the 
proboscis  is  inserted  in  another  flower  a  portion  of  the  pollen 

49 


THE  FLOWER  AND   THE  BEE 

is  lodged  on  a  receptive  part  of  the  stigma,  where  it  soon  germi- 
nates. 

The  pea  (Fig.  22),  bean,  clovers,  locust,  vetch,  alfalfa,  and  a 
host  of  leguminous  allies,  are  grouped  together  in  the  pea  family, 
or  Papilionaceoe — a  name  derived  from  the  Greek  word  for 
butterfly,  because  of  a  fancied  resemblance  of  the  flowers  to 
that  insect.  Most  of  the  5,000  described  species  are  bee- 
flowers,  although  there  are  a  few  bird  and  butterfly  flowers, 
and  at  least  13  species  are  known  which,  in  the  absence  of 
bees,  are  infertile.  For  the  most  part  9  of  the  10  stamens 
unite  to  form  a  tube,  at  the  bottom  of  which  lies  the  nec- 
tar, if  present.  Four  of  the  petals  interlock  around  this 
tube,  while  the  fifth,  called  the  standard,  is  broad  and  erect 
and  brilliantly  colored  to  attract  the  attention  of  insects.  In 
order  to  obtain  the  nectar,  a  bee  rests  upon  the  two  lateral 
wing-petals,  which  act  as  levers,  braces  its  head  against  the 
standard,  when,  if  it  is  strong  enough,  the  keel  is  depressed, 
and  it  may  introduce  its  tongue  in  an  opening  at  the  base  of  the 
staminal  tube.  In  this  family  the  pollen  is  applied  to  the 
under-side  of  a  bee's  body  in  four  different  ways :  It  may  es- 
cape through  a  valve,  or  it  may  be  pumped  out,  or  brushed 
out,  or  there  may  be  an  explosive  mechanism. 

But  what  if  it  is  not  strong  enough  to  depress  the  keel? 
Then  it  does  not  get  the  nectar.  Notwithstanding  their  beauti- 
ful hues  and  honey-like  perfume,  the  flowers  of  the  sweet  pea 
{Lathyrus  odoratus)  are  very  rarely  visited  by  bees.  Why  is 
this.'^  So  firm  is  the  closure  of  the  flower  that  only  a  very 
ppwerful  bee  is  able  to  depress  the  keel  and  obtain  the  nectar. 
Doubtless  in  its  transatlantic  home  (for  the  sweet  pea  is  not 
endemic  in  America)  there  are  bees  strong  enough  to  push 
open  the  flower.  During  one  summer  observations  continued 
for  several  weeks  failed  to  reveal  a  single  visit  by  any  species 

50 


1 

1 

1 

1 

1 

Fig.  21.     Pansy.     Viola  tricolor 
A  bee-flower;  yellow  flowers  with  dark-purple  centre 


THE  FLOWER  AND  THE   BEE 

of  bee.  But  in  late  September,  after  the  autumnal  honey-flow 
from  the  goldenrods  was  over,  I  repeatedly  saw  honey-bees 
examine  the  blossoms,  but  they  made  no  attempt  to  depress 
the  keel.  None  of  their  efforts  to  find  the  nectar  proved 
effectual.  Neither  are  the  bumblebees  more  successful.  But 
I  have  seen  a  queen  of  Bomhus  fervidus  visit  twenty  flowers  in 
succession, and  obtain  the  nectar  illegitimately  through  a  crevice 
between  the  standard  and  a  wing-petal.  Until  the  summer 
of  1912  I  did  not  suppose  that  there  was  a  single  species  of  our 
native  bees  which  could  pollinate  the  flowers.  But  in  Septem- 
ber a  female  leaf -cutting  bee  {Megachile  latimaniis),  a  large 
and  powerful  insect,  put  in  an  appearance.  She  easily  de- 
pressed the  keel  and,  thrusting  her  tongue  beneath  the  stand- 
ard into  the  staminal  tube,  sucked  the  nectar  for  a  long  time. 
She  was  so  fearless  that  I  was  able  to  stroke  her  back 
with  my  finger.  As  the  flowers  of  the  sweet  pea  are  easily 
self -pollinated,  they  are  very  prolific,  even  in  the  absence  of 
insects. 

Another  species  belonging  to  the  pea  family,  which  is  also 
pollinated  chiefly  by  leaf-cutting  bees,  is  alfalfa,  the  most  im- 
portant of  fodder-plants  in  the  West,  and  a  most  valuable 
source  of  honey  to  beekeepers.  The  flowers  are  known  as  ex- 
plosive flowers.  The  anthers  and  stigma  are  held  in  the  keel 
imder  tension.  When  a  bee  presses  down  the  wings  and  keel, 
it  has  been  described  as  pulling  two  triggers  and  firing  off  the 
flower,  that  is,  the  anthers  and  stigma  fly  forcibly  upward  and 
the  pollen  is  thrown  against  the  body  of  the  bee.  Three  leaf- 
cutting  bees  {Megachile  latimanus)  have  been  observed  to  trip 
the  flowers  at  the  rate  of  55^^  per  hour.  Honey-bees  make  a 
practice  of  stealing  the  nectar  through  a  hole  in  the  side  of  the 
corolla,  but  are  of  little  benefit  as  pollinators.  East  of  the 
Mississippi  alfalfa  yields  very  little  nectar,  but  in  the  Western 


Fig.  22.     Garden-Pea.     Pisnvi  sativum 
A  bee-flower,  probably  from  Asia;  in  America  it  is  usually  self-pollinated 


Fig.  23.     Alfalfa.     Medicago  sativa 

Cultivated  for  fodder,  yields  nectar  in  the  West,  but  not  in  the  East.     A  bee-flower, 
pollinated  chiefly  by  leaf-cutting  bees  and  bumblebees 


Fig.  24.     White  Clover.     Trifolium  re  pens 
First  stage;  all  the  flowers  point  upward.    The  most  important  honey-plant  in  North  America 


THE    FLOWER   AND   THE   BEE 

States  hundreds  of  tons  of  honey  are  stored  from  it  annually. 
(Fig.  23.) 

Many  of  the  flowers  of  the  pea  family,  in  fading,  undergo 
a  change  in  position  and  color.  In  the  white  clover  the  white 
central  flowers  contrast  with  an  older  outer  ring  of  rose-colored 
blossoms.  (Figs.  24  and  25.)  In  the  yellow  clover  the  newer 
flowers  contrast  with  a  ring  of  chestnut-brown.  In  the  wild 
vetch  (Vicia  Cracca)  the  older  flowers  bend  downward  and  turn 
from  violet-blue  to  dark  purple  (Fig.  26),  while  the  purple 
flowers  of  Desmodium  become  green  in  withering.  In  this  way 
the  bees  are  able  to  distinguish  the  older,  nectarless  flowers 
which  have  been  pollinated  from  those  w^hich  have  just  opened. 

In  the  mint  family  {Lahiatoe)  and  figwort  family  {Scrophu- 
lariacece)  the  flowers  stand  horizontal  and  are  more  or  less  two- 
lipped.  According  to  the  way  in  which  the  lips  have  developed 
the  larger  flowers  exhibit  strange,  fantastic  forms  which  mimic 
the  heads  of  reptiles  or  other  animals,  or  of  inanimate  objects. 
Such  are  the  turtlehead,  snapdragon,  monkey-flower  (Fig.  27), 
toadflax,  foxglove,  skullcap,  and  Calceolaria,  or  shoe-flower. 
(Fig.  28.)  A  great  many  species  are  pollinated  by  bees,  as  the 
hedge-nettle  {Stachys),  dead-nettle  {Lamium),  hemp-nettle 
(Galeop.ns),  the  sages,  cow-wheat  (Melampyrum),  and  the  loose- 
wort  {Pedicidaris).  (Figs.  29  and  30.)  A  goodly  number  are 
bumblebee-flowers,  some  exotic  species  are  bird-flowers,  the 
figworts  (Scrophularia)  are  wasp-flowers,  while  others  with 
small,  inconspicuously-lipped  corollas  are  fly-flowers,  as  the 
speedwells  and  mints. 

It  will  be  remembered  that  in  the  pea  family  by  means  of 
various  devices  the  pollen  was  placed  on  the  under-side  of  the 
bee's  body ;  but  in  the  mints  and  figworts  it  is  usually  deposited 
on  the  back  of  the  insect.  In  the  turtle-head  (Chelone  glabra) 
the  four  heart-shaped  anthers  lie  well  forward  in  the  angle 

56 


Fig.  25.     White  Clover.     Trifolhim  repens 
Second  stage;  after  pollination  the  flowers  bend  downward  and  turn  reddish,  then  brown 


Fig.  26.     Purple  Vetch.     Vicia  Cracca 
A  bee-flower,  common  in  fields 


BEES  AS  BUILDERS   OF   FLOAVERS 

formed  by  the  sides  of  the  upper  Up.  (Fig.  41.)  Their  inner 
faces  are  appHed  together  to  form  a  single  chamber  or  cavity 
into  which  the  pollen,  when  ripe,  falls.     The  contiguous  edges 


Fig.  27.     Two  varieties  of  Monkey-Flower.     Mimulus  luteus 

A  bee-flower 

are  densely  woolly  to  protect  the  pollen  and  to  prevent  the 
relative  displacement  of  the  anthers  by  connecting  the  first 
pair  above,  and  the  first  and  second  pairs  at  the  sides.     When 

59 


THE  FLOWER  AND   THE   BEE 

a  bumblebee  enters  the  flower  it  spreads  apart  the  arched 
filaments,  opening  the  pollen  receptacle,  and  covering  the 
thorax  with  fine  grains  of  pollen. 

Since  both  methods  of  lodging  the  pollen  on  the  body  of  a  bee 
have  proved  effective,  it  may  be  inquired  why  have  two  directly 
opposite  courses  been  followed  in  different  families.  To  answer 
this  question  it  is  necessary  to  go  back  to  an  early  stage  in  the 
history  of  the  pea,  mint,  and  figwort  families,  when  as  yet  the 
flowers  were  wheel-shaped  or  regular  in  form.  In  the  ancestral 
plants  from  which  the  pea  family  was  derived  the  stamens 
were  long  and  projected  far  out  of  the  corolla,  so  that  insects 
alighted  on  the  anthers  and  filaments,  pushing  them  downward. 
But  in  the  primitive  stock  of  the  mint  and  figwort  families  the 
stamens  were  short  and  nearly  included  in  the  corolla-tube. 
When  a  bee  rested  on  the  lower  lip  its  head  came  beneath  the 
anthers,  which  were  pushed  up  against  the  helmet,  just  the 
opposite  of  what  happened  in  the  pea  family.  The  pollen  was 
consequently  placed  on  the  bee's  back.  If  the  anthers  stood 
directly  within  the  entrance  to  the  corolla,  as  in  the  violet, 
then  the  bee  was  compelled  to  run  its  tongue  between  them. 
Thus  in  the  evolution  of  these  families  it  was  the  length  of  the 
stamens  which  determined  where  the  pollen  should  be  placed 
on  the  insect  visitor. 

Regular  flowers,  like  the  buttercup  and  rose,  always  stand 
vertical,  that  is,  if  erect  they  face  the  sky,  or  if  pendulous 
the  earth.  Irregular,  or  bilaterally  symmetrical  flowers,  on 
the  contrary,  always  stand  horizontal,  or  face  the  horizon. 
This  is  well  shown  in  the  dense  flower-cluster  of  the  horse-chest- 
nut, where  the  lateral  flowers  are  irregular  and  the  single 
terminal  flower  rotate  or  regular.  Vertical  flowers,  like  the 
borage  or  strawberry,  are  approached  by  insects  with  equal 
ease  from  every  side,  and  the  forces  which  might  change  their 

60 


" 

^^k  M 

i 

4\  7    ^^^^^'^^^^ 

plpHH^ 

Fig.  28.     Yellow  Calceolaria.     Calceolaria  scahioscefolia 
A  bee-flower;  the  corolla  is  two-lipped,  with  the  lower  lip  much  the  larger,  sac-shaped 


THE   FLOWER  AND   THE   BEE 

form  are  thus  held  in  equihbrium  or  counterbalance  each 
other.  But  where  the  flower  stands  horizontal,  as  the  snap- 
dragon or  the  sage,  bees  almost  invariably  land  on  the  lower 


Fig.  29.     Yellow  Rattle.     Rhinatithus  Crista-galli 

A  bee-flower 

Side  of  the  corolla.  As  a  consequence  one,  two,  or  three  of 
the  lower  petals  become  transformed  into  a  lip  which  serves 
as  a  landing-stage.     Such  an  adaptation  is  beneficial  to  both 

62 


BEES  AS   BUILDERS   OF   FLOWERS 

the  flowers  and  the  guests.  Contemporaneously  the  upper 
petals  were  modified  into  a  helmet,  or  galea,  to  protect  the 
anthers  and  the  interior  of  the  flower  from  wet — and  a  flower 


^^^^K'  4*-w    ^^Sli^^^^^^^^^^l 

IT""^^ 

CVKi. '^^P^  ''  .^^^^B^"        ''^'^^^^^^11 

^H|^:4  '      1 

^^^^^pRK'^III^^^^^^^^H 

Fig.  30.     Heal-All.    PruneUa  vulgaris 

A  violet-colored  bee-flower  belonging  to  the  mint  family 

like  the  snapdragon  is  evolved.  In  no  two  cases  were  the 
conditions  exactly  alike,  with  the  result  that  a  great  variety 
of  forms  has  been  produced,  each  of  which  has  its  special  ex- 

63 


THE   FLOWER   AND   THE   BEE 

planatioii.  Some  are  more  perfect  than  others,  while  some  have 
retrograded  and  lost  their  earlier  structure.  But  the  general 
principle  has  been  the  same,  although  it  has  been  worked  out  in 
manifold  ways.     (Figs.  31  and  3^.) 

"We  are  groping  here  to  find 
What  the  Thought  which  underlies 
Nature's  masking  and  disguise." 

But  all  bee-flowers  are  not  one-sided  (zygomorphous)  or  irreg- 
ular. They  may  be  funnel-formed  as  in  the  gentians,  or  urn- 
shaped  as  in  the  checkerberry  and  blueberry,  or  even  wheel- 
shaped  as  in  the  common  borage,  or  regularly  spurred  as  in  the 
pendulous  flowers  of  the  columbine.     (Fig.  38.) 

It  is  a  remarkable  fact  that  bee-flowers  are  more  often  blue 
than  any  other  color.  Let  us  look  at  the  colors  of  these  flowers 
in  the  Northern  States.  Of  34  species  of  violets  17  are  blue, 
4  blue-purple,  6  yellow,  and  7  white.  Of  197  species  belonging 
to  the  pea  family  {Papilionaceop)  '24  are  blue,  88  blue-purple, 
13  red,  33  yellow,  and  39  white.  Of  I'^O  species  of  the  mint 
family  {Labiatw)  33  are  blue,  47  blue-purple,  1*2  red,  4  yellow, 
and  ^24  white.  Of  the  113  species  of  the  figwort  family  {Scro- 
phidoriaceGp)  28  are  blue,  3*2  blue-purple,  7  red,  33  j^ellow,  and 
13  white. 

On  the  other  hand,  neither  bee  nor  blue  flowers  occur  in  the 
pink  and  rose  families.  In  the  immense  orchis  family,  in  which 
bee-flowers  are  of  comparatively  rare  occurrence,  there  is  only 
one  blue  flower,  Vcmda  coerulea,  from  India.  In  this  family 
red  is  developed  much  more  easily  than  blue.  It  should  be 
added  that,  when  two  or  more  species  of  bee-flowers  belonging 
to  the  same  genus  blossom  simultaneously  in  the  same  locality, 
they  are  frequently  unlike  in  color,  as  the  red,  white,  and  yellow 
clovers.  This  diversity  of  color  facilitates  the  efforts  of  the 
bee  to  remain  constant  to  one  species. 

64 


BEES  AS   BUILDERS   OF   FLOWERS 


If  you  inquire  why  bee-fiowers  are  so  often  blue,  I  shall  be 
compelled  to  admit  that  I  do  not  know  with  certainty.  It  is 
a  problem  which  still  awaits  further  study.  Some  naturalists 
have  said  that  bees 
prefer  blue  to  every 
other  color,  Avhile 
others  claim  that  it  is 
merely  an  incidental 
result  correlated  with 
the  higher  specializa- 
tion of  the  flower. 
For  example,  in  the 
animal  kingdom,  white 
cats  (if  they  have  blue 
eyes)  are  nearly  always 
deaf,  but  no  one  knows 
why. 

Bee-flowers  are  usu- 
ally marked  with  spots 
or  lines  called  "nectar- 
guides,"  which  point 
out  the  w  ay  to  the  nec- 
tar. (Fig.  34.)  In  the 
snapdragon  the  pal- 
ate is  yellow;  in  the 
pickerel-weed  there 
are  two  bright-yellow 
spots    on    the    middle 

lobe  of  the  upper  lip;  in  the  turtle-head  the  white  corolla  has 
reddish  lips.  The  flower  of  the  hedge-nettle  {Stachys  erecta)  is 
yellowish  white,  with  the  border  of  the  upper  lip  marked  with 
two  purple  stripes  and  the  lower  lip  purple-spotted.    The  flower 

65 


Fig.  3L     Pink-Fringed  Polygala.     Polygala 
fan  ci folia 

A  liee-flower.     The  crest,  or  frinije,  is  well  shown  in  the 
photograph 


Fig.  32.     Pink  Lady's-Slipper.     Cypripedium  acaiile 

This  flower  is  pollinated  by  small  bees,  which  gain  an  entrance  at  the  front  €nd  of  the  slipper 
and  pass  out  through  two  small  holes  at  its  base 


Fig.  33.     Sheep-Laurel.     Kalmia  angustifolia 

A  regular  or  wheel-shaped  bee-flower.  The  stamens  are  elastic  and  when  touched  by 
the  legs  of  a  bee  the  anthers,  which  are  held  in  little  pockets  in  the  corolla,  are  re- 
leased and  fly  upward,  throwing  the  pollen  over  the  bee 


THE   FLOWER  AND   THE  BEE 

of  the  dead-nettle  {Lamium  album)  is  large,  white  or  sometimes 
rose-colored,  with  the  under  lip  pale  yellow,  marked  with  olive- 
colored  dots;    while  the  flowers  of  the  hemp-nettle  {Galeopsis 


Fig.  34.     Foxglove.     Digitalis  purpurea 
A  bumblebee-flower,  with  the  corolla  spotted  on  the  lower  inner  side 

Tetrahit),  so  common  in  waste  places,  is  purple,  with  a  path- 
finder on  the  lower  lip  of  a  yellow  spot  crossed  by  a  network 
of  red  lines. 

The  marvellous  adaptations  of  flowers  for  effecting  pollina- 
tion, both  by  their  variety  and  ingenuity,  fill  us  with  astonish- 
ment, and  occasionally  they  surpass  the  bounds  of  the  wildest 
imagination.  The  opening,  maturity,  and  fading  of  the  flower, 
the  various  movements  of  its  organs,  the  allurements  of  color, 
odor,  and  nectar,  and  the  behavior  of  the  insect  guests,  which 


BEES  AS   BUILDERS   OF   FLOWERS 

may  number  from  one  to  more  than  three  hundred,  afford  an 
endless  field  for  observation.  Flowers  cease  to  be  merely  bright 
bits  of  color  in  the  landscape  when  we  know  their  life  histories, 
their  rivalries,  and  tragedies;  and — yes,  their  comedies — we 
see  as  upon  the  stage  reflections  of  our  own  experiences.  There 
is  no  more  fascinating  study  than  entering  the  secret  chambers 
of  these  bright-hued  floral  edifices  which  adorn  our  fields  and 
gardens  and  probing  the  mysteries  which  there  confront  us. 
But  we  should  seek  the  living  blossoms, 

"Each  one  of  the  beautiful  flower  faces,"  says  Hermann 
Mueller,  "which  we  were  wont  to  marvel  at  with  a  sad  feeling 
of  resignation  as  so  many  mysteries  forever  veiled  now  looks 
upon  us,  inspiring  hope,  and  stimulates  us  in  friendly  wise  to 
cheerful  perseverance,  as  if  it  would  say,  'Only  venture  to  come 
to  me,  and  in  true  love  make  yourself  acquainted  with  me  and 
all  my  conditions  of  life,  as  intimately  as  you  may,  and  I  am. 
ready  to  let  fall  the  veil  that  hides  me,  and  trust  myself  and  all 
my  secrets  to  you. '" 

"Think  of  all  these  treasures. 

Matchless  works  and  pleasures. 
Every  one  a  marvel,  more  than  thought  can  say; 

Then  think  in  what  bright  showers 

We  thicken  fields  and  bowers. 
And  with  what  heaps  of  sweetness  half  wanton  May. 

Tliink  of  the  mossy  forests 

By  the  bee-l)irds  haunted. 
And  all  those  Amazonian  plains,  lone  lying  as  enchanted.'' 


69 


CHAPTER  V 
BUMBLEBEE-FLOWERS 

THE  English  nation  owes  its  power  and  wealth  largely 
to  bumblebees.  This  statement  sounds  a  bit  sensa- 
tional, not  to  say  improbable.  But  it  was  the  opinion 
of  a  distinguished  German  scientist,  Carl  Vogt,  and  is  indorsed 
by  an  eminent  living  biologist,  Ernst  Haeckel,  of  Jena.  Let  us 
examine  the  evidence. 

Red  clover  {Trifolium  pratense)  is  chiefly  pollinated  by  bum- 
blebees, and  is,  therefore,  called  a  bumblebee-flower.  (Fig. 
35.)  In  the  absence  of  bumblebees  this  valuable  and  exten- 
sively cultivated  fodder-plant  yields  little  or  no  seed,  as  may  be 
easily  proven  by  covering  a  small  bed  of  red  clover  with  netting 
to  exclude  bees.  According  to  Carl  Vogt,  one  of  the  most 
important  foundations  of  the  wealth  of  England  is  found  in  the 
cattle,  which  feed  principally  on  red  clover.  "Englishmen," 
says  Haeckel,  "preserve  their  bodily  and  mental  powers  chiefly 
by  making  excellent  meat — roast  beef  and  beefsteak — their 
principal  food.  The  English  owe  the  superiority  of  their  brains 
and  minds  over  other  nations  to  their  excellent  meat."  There 
is  no  need  to  enter  here  into  any  discussion  as  to  whether 
Haeckel's  logic  is  sound  or  not,  but  it  will  be  hardly  denied 
that  the  production  of  this  meat  depends  to  a  great  extent  on 
the  industrious  bumblebee. 

Incidentally  it  may  be  added  that  Darwin  pointed  out  that 
the  number  of  bumblebees  in  England  was  determined  by  the 
number  of  cats.  Mice  rob  bumblebees'  nests  and  are  in  turn 
killed  by  cats;  consequently  if  there  are  few  cats  there  are 
many  mice  and  few  bumblebees.     Here  Huxley  suggested  that, 

70 


BUMBLEBEE-FLOWERS 

as  old  maids  are  fond  of  cats,  and  nsually  keep  one  or  more  of 
these  animals  as  pets,  it  depended  on  them  whether  there  should 
be  an  abundant  crop  of  red  clover  or  not.  Let  us,  then, 
chivalrously  admit  that,  as  in  the  bee-hive  or  bumblebee's  nest, 
the  existence  of  the  colony  depends  on  the  workers,  or  unmated 
females,  so  the  prosperity  of  England  depends  on  her  old  maids. 
It  is  certainly  a  curious  instance  of  the  intimate  correlation  of 
every  part  of  nature. 

When  the  farmers  of  New  Zealand  attempted  to  grow  red 
clover  in  their  fields  they  learned  to  their  cost  its  dependence 
on  bumblebees  for  pollination,  for  it  failed  to  produce  seed.  On 
inquiry  it  was  learned  that  there  were  no  bumblebees  in  these 
large  islands,  and  it  was  not  until  after  the  introduction  of 
several  species  from  England  that  the  raising  of  clover-seed 
became  commercially  profitable.  Once  introduced,  the  bumble- 
bees multiplied  apace;  and  a  few  years  ago  a  letter  appeared 
in  one  of  the  New  Zealand  papers  complaining  that  they  were 
becoming  so  numerous  that  they  threatened  to  consume  the 
nectar  of  all  the  flowers  and  leave  none  for  the  domestic  bee. 
But  the  alarm  proved  groundless,  for  in  1905  the  Canadian 
Department  of  Agriculture  received  a  letter  from  the  secretary 
of  an  agricultural  association  in  New  Zealand  inquiring  what 
species  of  Bomhus  pollinated  the  red  clover  in  that  country. 
Three  species  of  bumblebees  {Bomhus  terrestris,  B.  hortorum, 
and  B.  hortorum  variety  harrisellus),  descended  from  those  im- 
ported in  1885,  are  stated  to  occur  in  New  Zealand;  but  B. 
terrestris,  the  most  abundant  species,  was  regarded  as  unsuit- 
able for  clover  pollination  owing  to  the  shortness  of  its  tongue. 
It  was  believed  that  the  best  results  had  not  yet  been  obtained, 
and  that  it  was  desirable  to  introduce  longer-tongued  species. 
Of  American  species  Bomhus  americayiorum  and  B.  fervidus  ap- 
pear well  adapted  for  this  purpose. 

71 


THE   FLOWER  AND   THE  BEE 

To-day  bumblebees  benefit  the  islands  of  New  Zealand 
annually  to  the  extent  of  many  thousand  dollars.  Fields  which 
were  almost  barren  in  their  absence  now  produce  great  quan- 
tities of  seed.  At  Canterbury  36  acres  of  red  clover  were  the 
resort  of  thousands  of  bumblebees,  and  yielded  400  to  500 
pounds  of  seed  per  acre.  In  one  province  alone,  in  1912,  610 
acres  were  sown  with  red  clover,  which  it  is  estimated  yielded 
an  average  of  158  pounds  to  the  acre. 

The  nectar  of  red  clover  is  secreted  at  the  base  of  a  floral 
tube  a  little  over  9  mm.  long,  where  it  is  beyond  the  reach 
of  honey-bees,  which  have  a  tongue  only  about  6  mm.  in  length. 
Under  normal  conditions,  then,  honey-bees  do  not  resort  to 
the  red-clover  fields;  but  occasionally  in  very  dry  weather  the 
floral  tubes  become  so  short  that  large  yields  of  honey  are  ob- 
tained. Two  or  three  times  during  the  past  thirty  years  at 
Borodino,  N.  Y.,  red  clover  has  been  a  very  valuable  source 
of  honey;  and  one  season  full  60  pounds,  on  an  average,  to  a 
colony  was  obtained.  A  very  remarkable  illustration  of  the 
relation  of  rainfall  to  the  length  of  the  corolla-tubes  of  red  clover 
was  observed  by  an  apiarist  at  Medina,  Ohio.  One  of  his 
apiaries  was  located  near  Medina,  and  another  about  two  miles 
north  of  that  city.  A  few  years  ago  there  was  a  drought  at 
the  north  bee-yard,  and  the  floral  tubes  of  the  red  clover  were 
so  much  shorter  than  usual  that  honey-bees  were  able  to  reach 
the  nectar.  When  one  of  the  farmers  began  to  cut  his  field  of 
red  clover  that  season,  the  cutter  knives  of  the  mower  stirred 
up  so  many  bees  that  they  attacked  the  horses  and  their  driver. 
Singularly  enough  at  Medina  and  the  south  bee-yard  there  was 
an  abundance  of  rain.  The  red  clover  made  a  luxuriant  growth, 
and  the  floral  tubes  were  so  long  that  the  bees  could  not  obtain 
the  nectar,  and  consequently  there  were  none  on  the  clover- 
heads.     Thus  two  bee-keepers,  living  only  a  few  miles  apart, 

72 


Fig.  85.     Red  Clover.     Trifolium  pratense 

A  bumblebee-flower 


THE   FLOWER  AND   THE   BEE 

might  have  arrived  at  diametrically  opposite  conclusions  as  to 
the  value  of  red  clover  as  a  honey -plant. 

Three  other  genera  of  very  common  bumblebee-flowers  may 
be  found  in  almost  any  old-fashioned  garden.  They  are  the 
larkspurs  {Delphinmm) ,  the  aconites,  or  monk's-hoods  (Aconi- 
tum),  and  the  columbines  {Aquilegia).  They  all  agree  in  hav- 
ing the  nectar  concealed  in  long  spurs  or  nectaries,  which  vary 
in  length  in  the  different  species.  The  tongues  of  the  various 
species  of  bumblebees  also  differ  in  length,  ranging  in  the 
workers  from  jq  to  ie  of  an  inch.  In  the  females,  or  queens, 
the  tongue  is  still  longer,  and  in  the  garden-bumblebee  of  Eu- 
rope reaches  the  length  of  it  of  an  inch. 

Of  our  hardy  perennials  there  are  few  which  produce  a  more 
stately  effect  than  the  bee-larkspur  {Delphinium  elatum)  with 
its  wand-like  racemes  of  deep-blue  flowers.  This  plant  is  a 
native  of  Europe,  where  it  is  pollinated  by  the  female  of  the 
garden-bumblebee,  no  other  bee  on  the  wing  at  the  time  it 
blooms  having  a  tongue  long  enough  to  reach  all  of  the  nectar, 
although  a  part  of  it  is  accessible  to  a  few  other  bees.  I  have 
seen  honey-bees  searching  the  flowers  and  pushing  their  tongues 
down  into  the  long  spurs  as  far  as  possible,  but  they  were  never 
able  to  gain  any  of  the  sweet  spoil.     (Fig.  36.) 

The  aconites,  or,  as  they  are  perhaps  better  known,  the 
monk's-hoods,  are,  says  Kronfeld,  bumblebee-flowers  par  ex- 
cellence. When  a  plaster-cast  is  made  of  the  inside  of  a  flower 
it  is  found  to  correspond  almost  exactly  to  the  shape  of  a 
medium-sized  bumblebee.  This  genus  of  plants  is  so  depen- 
dent on  bumblebees  for  pollination  that  it  is  absent  from  those 
parts  of  the  world  where  there  are  no  bumblebees.  For  in- 
stance, there  are  no  native  bumblebees  in  Australia,  Arabia, 
South  Africa,  and  New  Zealand,  and  in  these  countries  there 
are  no  indigenous  species  of  Aconitum.     (Fig.  37.) 

74 


Fig.  36.     Bee-Larkspur.     Delphinium  elatum 
A  bumblebee-flower 


THE   FLOWER  AND   THE   BEE 

The  columbines  manage  to  thrive  and  bloom  under  the  most 
difficult  conditions  of  soil  and  climate.  The  long  spurs  of  the 
variously  colored,  pendulous  flowers  of  the  garden-columbine 


Fig.  37.     Monk's-Hood.     Acomtum  Nopelhis 

A  bumblebee-flower 


(Aqiiilegia  vulgario)  are  rich  in  nectar  and  are  great  favorites  of 
bumblebees.  (Fig.  38.)  Sometimes  they  bite  holes  in  the 
spurs  in  order  to  save  time,  and  then  the  honey-bees  also  come 
and  suck  the  nectar  through  these  punctures.  Our  wild  colum- 
bine {A.  canadensis)  has  scarlet  flowers  which  are  yellow  inside, 
or  rarely  all  over,  and  is  chiefly  visited  by  humming-birds. 

76 


BUMBLEBEE-FLOWERS 


Other  iialive  Iminiuing-bird  flowers  are  the  cardinal-flower, 
the  truiiii^et-honeysuckle,  the  painted  cup,  and  the  trumpet- 
flower;  but  bird-flowers  are  not  common  in  North  America, 
although  abundant  in  tropical  South  America. 

Another  common  bumblebee-flower  is  the  garden-nasturtium. 


Wfn 

l^^^^m      ''*^ 

l^^'fl 

^^^^^D^^^^dl^^^^^^^^^^^HI 

^^^^^^^l^v'-i:  '-'^'  ifl^B^^^^H 

Fig.  38. 


White  Garden-Columbine. 
A  bumblebee-flawer 


AquUegia  vulgar 


The  lower  part  of  each  petal  is  marked  with  red,  which  serves 
as  a  guide  to  the  nectar;  while  the  claws  of  the  lower  petals  are 
fringed  with  hairs  which  prevent  water  from  running  into  the 
spur.  Honey-bees  cannot  reach  the  nectar,  although  they 
occasionally  attempt  to  do  so,  for  only  bumblebees  with  the 


THE   FLOWER   AND   THE   BEE 

longest  tongues  can  obtain  all  of  it.  The  spur  is  so  tough  that 
it  cannot  be  perforated.  Honey-bees  gather  pollen  from  the 
anthers,  which  open  one  at  a  time  rising  successively  before  the 
mouth  of  the  flower. 

The  snapdragon  {Antirrhinum  ma  jus)  is  another  bumblebee- 
flower  widely  cultivated  in  gardens.  So  firmly  are  the  Hps 
closed  together  that  the  smaller  bees  cannot  force  them  apart, 
and  thus  the  nectar  is  protected  for  the  rightful  guests.  But 
as  the  flowers  grow  older  the  lips  part  slightly,  and  then  the 
smaller  bees  are  able  to  force  an  entrance.  The  great  size  of 
the  corolla  permits  the  largest  bumblebees  to  creep  wholly 
within  it.     (Fig.  40.) 

A  typical  wild  bumblebee-flower  is  the  turtle-head  {Chelone 
glabra),  which  grows  along  the  banks  of  streams  and  in  marshes. 
The  large,  white  flowers  rudely  mimic  in  form  the  head  of  a 
turtle.  Although  I  have  had  them  under  observation  for  many 
hours  and  on  many  different  occasions  I  have  never  seen  them 
entered  by  any  insects  except  bumblebees.  Wasps  and  flies 
sometimes  examine  the  lips,  which  are  tinged  with  yellow,  ap- 
parently looking  for  nectar;  but  they  never  pass  between  them 
into  the  corolla-chamber.  The  mouth  of  the  flower  is  so  small 
that  a  bumblebee  sometimes  finds  difficulty  in  entering,  but 
once  inside  there  is  an  abundance  of  room  for  a  bee  to  turn 
completely  around.  I  once  placed  several  flower-clusters  of 
the  turtle-head  in  a  glass  of  water  a  few  feet  in  front  of  a  bee- 
hive; but  of  the  many  honey-bees  constantly  coming  and  going 
not  one  of  them  entered  a  flower.  But  presently,  notwith- 
standing their  unusual  position,  every  blossom  was  examined  by 
bumblebees.  The  honey-bees  seemed  instinctively  to  know 
that  these  flowers  were  not  designed  for  their  use.      (Fig.  41.) 

The  common  "touch-me-not,"  or  jewelweed  {Impatiens 
hiflora)  which  covers  acres  of  damp  land,  is  another  bumble- 

78 


Fig.  39.     Tartarian  Honeysuckle.     Lonicera  tartarica 
A  bumblebee-flower 


THE  FLOWER  AND   THE   BEE 

bee-flower,  much  sought  after  by  Bomhus  vagans  and  B.  terri- 
cola.  Its  brown-spotted,  orange  blossoms  are  shaped  Hke  a 
horn  of  plenty  with  the  spur  inflexed  or  bent  inward  beneath 
it.  The  flower  is  suspended  horizontally,  with  the  anthers  and 
stigma  lying  on  its  upper  side,  so  that  when  a  bee  enters  the 
dilated  corolla-sac  its  back  is  dusted  with  pollen  which  is  carried 
away  to  another  flower.  It  is  a  matter  of  some  difficulty  and 
delay  for  bumblebees  to  enter  the  flowers,  and  very  likely  the 
short-tongued  workers  are  not  able  to  reach  all  of  the  nectar; 
so  after  a  little  while  they  bite  holes  in  the  spurs  and  steal  the 
sweet  contents.  On  August  10  I  examined  a  large  number  of 
flowers,  but  none  of  the  nectaries  were  punctured  and  they  were 
visited  normally  by  Bomhus  vagans,  or  the  wandering  bumble- 
bee, at  the  rate  of  7  to  12  visits  per  minute.  But  during  the 
latter  part  of  August  I  found  hundreds  of  the  spurs  perforated 
and  both  bumblebees  and  honey-bees  gathering  the  nectar 
from  these  punctures.  (This  habit  led  Mueller  to  call  the  bum- 
blebee an  "anti-teleologist.")  A  honey-bee  was  watched  dur- 
ing 25  successive  visits,  and  not  once  did  it  even  make  a  pre- 
tense of  entering  the  flower;  but  in  every  instance  it  swung 
itself  astride  of  the  spur,  pushed  its  tongue  through  the  punc- 
ture and  became  literally  a  flower-robber.  Ten  such  visits 
may  be  made  in  a  minute.     (Fig.  42.) 

If  after  the  manner  of  plants  famous  in  myth  and  story  the 
Impatiens  (fitly  called  "touch-me-not"  in  this  respect)  could 
speak,  what  a  protest  it  would  utter !  For  unknown  centuries 
this  floral  edifice  has  been  under  construction,  only  at  the  last 
to  have  its  usefulness  threatened  by  a  change  in  the  habits  of 
its  bee  visitors.  Humming-birds  also  visit  the  flower,  while 
small  beetles  and  spiders  occasionally  seek  shelter  in  the  sac. 

But  not  all  bumblebee-flowers  are  irregularly  shaped.  The 
closed  gentian  and  the  fringed  gentian,  both  of  which  are  pol- 

80 


Fig.  40.     Snapdragon.     Antirrhinum  majus 
A  bumblebee-flower 


i'lG.  41.     Turtle-Head.     Chelonc  gJuhra 
A  bumblebee-flower 


BUMBLEBEE-FLOWERS 

linated  by  bumblebees,  are  funnel-formed.  The  gentians  bloom 
at  the  close  of  autumn  and  are  very  abundant  in  the  Alps, 
where  they  display  broad  expanses  of  blue  color.     The  closed 


Fig.  4i2.     Jewelweed.     Impatiens  hiflora 
A  bumblebee-flower 


gentian  never  opens,  and  on  a  cold  morning  the  temperature 
within  the  corolla-chamber  is  often  several  degrees  above  that 
of  the  outside  atmosphere.  The  fringe  on  the  edge  of  the  co- 
rolla of  the  fringed  gentian  prevents  the  ingress  of  small  injuri- 
ous insects.     (Fig.  43.) 

83 


THE  FLOWER  AND  THE  BEE 

Other  familiar  bumblebee -flowers  are  the  beautiful  Rhodora 
canadensis,  which  is  j^ollinated  in  spring  by  queen  bumblebees, 
the  only  caste  of  bumblebees  then  on  the  wing,  for  the  males 
and  workers  do  not  appear  until  later  (Figs.  44  and  45);  the 
fly-honeysuckle  {Lonicera  ciUata),  also  pollinated  in  May  by  fe- 
male bumblebees,  which  in  their  haste  to  get  the  nectar  often 
cut  the  buds  into  shreds;  the  Tartarian  honeysuckle  {Lonicera 
Tartarica)  of  the  garden  (Fig.  39);  the  bog  fly-honeysuckle 
{Lonicera  ccerulea);  the  bush-honeysuckle  {Diervilla  trifida),  the 
yellow  flowers  of  which  turn  red  in  fading;  the  horse-chestnut; 
the  foxglove;  and  the  Gladiolus. 

The  garden-bean  is  largely  self-fertilized,  but  bumblebees 
visit  the  flowers  more  or  less;  the  scarlet  runner  is  also  a  bum- 
blebee-flower, although  honey-bees  are  often  able  to  gather 
a  little  of  the  nectar.  The  lungwort  {Pidmonaria  officinalis), 
belladonna  {Atropa  belladonna),  the  bearberry  (Arctostaphylos 
Uva-ursi),  the  wood-betony  {Pedicidaris  sylvatica),  gill-over-the- 
ground  {Glechoma  hederacea),  and  largely  butter-and-eggs 
(Linaria  indgaris)  are  bumblebee-flowers.  The  scarlet  sage 
(Salvia  pratensis),  with  its  walking-beam  mechanism  for  placing 
the  pollen  on  a  bee's  back,  the  dragon's-head  {Dracocephalum, 
3  species),  Molucca  balm  (Moluccella  loevis),  bugle  {Ajuga  rep- 
tans),  and  several  orchids,  as  the  showy  orchis  {Orchis  spec- 
tabilis),  the  i:)ink  flowers  of  Pogonia  ophioglossoides  common  in 
bogs,  and  Calypso  borealis  are  all  pollinated  by  bumblebees. 
The  pretty  flowers  of  the  purple  Gerardia  {Gerardia  purpurea) 
are  abundant  in  autumn,  but  they  contain  little  nectar  and  few 
bumblebees  visit  them.  .  Finally  there  may  be  added  to  the 
list  Cerinthe  alpina,  Scopolia  atropoides,  and  black  henbane 
{Hyoscyamns  niger) . 

No  matter  how  bizarre  or  grotesque  a  bumblebee-flower  may 
be  to-day,  it  is  derived  from  a  primitive  form  that  was  per- 

84 


Fig.  43.     Fringed  Gentian.     Gentiana  crinita 

A  bumblebee-flower 


BUMBLEBEE-FLOWERS 

fectly  regular,  to  which  it  may  occasionally  revert.  The  colum- 
bine sometimes  produces  five  flat,  instead  of  five  spurred  petals, 
and  there  is  a  stellate  form  in  cultivation.  Even  the  larkspurs 
and  monk's-hoods  may  become  perfectly  regular.  A  regular 
form  of  the  snapdragon  was  cultivated  at  one  time  and  called 
"the  wonder."  Darwin  crossed  the  regular  forms  with  their 
own  pollen  and  raised  a  whole  bed  of  similar  flowers.  In 
Linaria,  or  butter-and-eggs,  reversion  to  a  radiate  form  often 
occurs  in  many  species.  Even  the  grotesque  orchids  untwist 
themselves  and  display  regular  star-shaped  flowers,  which  is 
the  normal  form  in  Dendrohium  normale.  Any  unsymmetrical 
flower  may  at  times  become  symmetrical,  that  is,  in  the  history 
of  the  evolution  of  flowers  radiate,  or  star-shaped,  flowers  are 
more  primitive  than  one-sided  or  bisymmetrical  flowers. 

Notwithstanding  the  industry  and  immense  numbers  of  the 
honey-bee,  there  are  no  flowers  adapted  to  this  species  alone. 
It  is  impossible  not  to  inquire  why  there  should  be  bumblebee- 
flowers,  but  no  honey-bee  flowers.  Should  we  not  rather 
expect  the  reverse.^  But  on  inquiry  into  the  economy  of  the 
honey-bee  the  reason  is  evident  enough.  The  domestic  bee 
requires  large  quantities  of  stores,  and  in  order  to  obtain  them 
it  must  visit  a  great  variety  of  flowers  throughout  the  entire 
season.  For  this  purpose  a  tongue  of  medium  length  is  far 
more  useful  than  a  longer  one.  If  the  tongue  is  very  long  the 
nectar  in  open,  wheel-shaped  flowers  like  the  strawberry  and 
basswood  can  be  sucked  up  only  with  diflSculty  and  delay. 
To  be  sure,  they  would  be  able  to  obtain  some  nectar  now  in- 
accessible, as  from  bumblebee-flowers  like  the  red  clover,  or 
from  moth-flowers  like  the  climbing  honeysuckle,  but  this 
would  not  compensate  for  the  disadvantages  sustained.  If  a 
longer  tongue  would  have  been  beneficial  to  the  honey-bee. 
Nature  would  have  long  since  developed  one.     Apiarists  can- 

87 


THE  FLOWER   AND   THE   BEE 

not  improve  on  the  tongue  of  the  honey-bee,  nor  can  they  pro- 
duce a  permanent  strain  of  red-clover  bees.  Taken  as  a  whole, 
and  under  all  conditions,  the  tongue  of  the  honey-bee,  as  it 
exists,  is  much  better  adapted  for  the  work  to  be  done  than  any 
that  can  be  produced  by  artificial  selection.  But  there  would 
seem  to  be  no  reason  why  a  variety  of  red  clover  with  shorter 
corolla-tubes  should  not  be  obtained. 


88 


CHAPTER  ^'I 
THE   GATHERING   OF  THE   NECTAR 

DURING  the  honey-flow  from  white  clover,  basswood, 
alfalfa,  sage,  goldenrod,  or  any  other  honey-plant 
which  yields  nectar  copiously  the  most  intense  excite- 
ment and  activity  prevails  in  the  apiary.  Work  begins  early 
in  the  morning  and  continues  until  late  in  the  afternoon.  The 
air  is  filled  with  thousands  of  bees  rushing  to  and  from  the  fields, 
and  the  roar  of  their  wings  may  be  heard  at  a  distance  from  the 
hives.  Oblivious  to  everything  else,  they  are  obsessed  with 
the  single  purpose  of  garnering  the  golden  store;  and  so  dili- 
gently do  they  labor  that  the  life  of  a  worker  bee  during  the 
summer  is  only  forty  days,  whereas  in  winter  they  may  live  for 
six  months  or  more.  In  a  colony  of  50,000  bees  it  has  been 
estimated  that  there  are  30,000  field-bees,  and  if  each  fielder 
makes  ten  trips  a  day  then  there  would  be  a  total  of  300,000 
visits  to  flowers  in  a  single  day.  About  37,000  loads  of  nectar 
are  required  for  the  production  of  a  pound  of  honey,  and, 
according  to  the  locality,  a  hive  may  gain  from  1  to  10  pounds  of 
honey  in  a  day.  It  is  clear  that  even  a  very  slight  saving  of 
time  or  labor  becomes  in  the  aggregate  of  great  importance 
to  the  colony. 

It  is  the  diligence  and  skill  of  bees — honey-bees,  bumblebees, 
and  solitary  bees — in  visiting  flowers  which  makes  them  the 
most  valuable  of  pollinators.  They  learn  quickly  from  observa- 
tion and  are  subsequently  guided  by  the  memory  of  past  experi- 
ence. Buckwheat  secretes  nectar  freely  during  the  forenoon 
and  attracts  thousands  of  bees;    but  during  the  afternoon  the 

89 


THE  FLOWER  AND   THE  BEE 

flow  entirely  ceases  and  the  bees  promptly  discontinue  their 
visits.  "In  spite  of  the  shimmering  sea  of  flowers,  in  spite  of 
the  strong  fragrance,  only  a  few  bees  can  be  found  in  the  buck- 
wheat-field after  twelve  o'clock."  Again,  a  sudden  shower  fol- 
lowed by  a  fall  in  temperature  may  bring  the  buckwheat 
harvest  to  an  abrupt  and  premature  close  in  August,  when  or- 
dinarily it  would  continue  into  September.  The  bees  then 
immediately  cease  visiting  the  flowers  and  in  countless  num- 
bers attempt  to  rob  each  other;  the  time  of  their  visits  thus 
always  coincides  with  the  period  of  active  secretion  of  nectar. 
(Fig.  46.) 

The  rapidity  with  which  bees  visit  flowers  is  greatly  influenced 
by  their  form  and  arrangement.  Honey-bees  cannot  reach 
the  nectar  of  the  yellow  and  red  garden-nasturtiums,  which  lies 
at  the  bottom  of  a  long  calycine  spur  and,  consequently,  are 
seldom  seen  on  the  flowers,  although  occasionally  they  come  for 
pollen.  One  of  the  larger  bumblebees  {Bombus  fervidus),  which 
has  a  tongue  12  mm.  long,  on  the  contrary  devotes  itself  ex- 
clusively to  sucking  nectar  and  ignores  the  pollen.  It  is  rather 
clumsy  in  its  movements  and  visits  only  from  1*2  to  14  flowers 
per  minute.  The  bilabiate  flowers  of  the  pickerel-weed  {Ponte- 
deria  cordaia)  are  examined  much  more  rapidly  by  a  smaller 
species  of  bumblebee  {Bombus  vagans).  In  July  the  violet-blue 
spikes  of  this  aquatic  plant  fringe  the  banks  of  many  northern 
streams  in  countless  numbers.  Bombus  vagans  is  a  very  common 
visitor,  beginning  always  with  the  lowest  flowers  of  the  spike 
and  working  upward.  By  actual  count,  several  times  re- 
peated, I  found  that  the  average  number  of  visits  per  minute 
was  about  70.  The  small  florets  of  the  goldenrods  are  visited 
so  rapidly  that  the  number  per  minute  cannot  usually  be 
counted.  But  when  the  nectar  is  very  abundant,  as  in  the 
flowers  of   the  basswood,  century -plant,  spider-plant  (Cleome 

90 


Fig.  4G.     Buckwheat.     Fagopyrnm  escidentum 
Secretes  nectar  only  during  the  forenoon;  yields  a  dark  honey,  about  the  color  of  molasses 


THE  FLOWER  AND  THE  BEE 

spinosa),  and  some  species  of  Eucalyptus,  a  honey-bee  may  ob- 
tain a  load  from  2  or  3,  or  even  1  flower. 

Bees  in  collecting  pollen  and  nectar  are  faithful  as  a  rule  to 
a  single  species  of  flower — they  exhibit  "flower  fidelity."  This 
is  for  their  advantage  since,  if  they  were  constantly  passing 
from  flowers  of  one  form  to  those  of  another,  much  time  would 
be  lost  in  locating  the  nectar.  At  the  same  time  the  flowers 
are  cross-pollinated  and  a  waste  of  pollen  is  prevented.  Even 
whole  colonies  may  be  true  to  a  single  species.  iVt  Ventura, 
Cal.,  in  1884,  1  colony  out  of  200  gathered  exclusively  from 
an  abundance  of  mustard-bloom,  while  199  gathered  from  the 
sages. 

But  where  there  are  several  differently  colored  varieties  of 
the  same  species,  honey-bees  soon  learn  to  visit  them  indis- 
criminately. Zinnia  elegans  displays  white,  yellow,  red,  and 
purple  varieties;  Dahlia  variabilis  white,  yellow,  orange,  red, 
and  purple;  and  Centaurea  Cyanus  (bachelor's-button)  red, 
white,  blue,  and  purple.  Bees  pass  freely,  in  visiting  these 
flowers,  from  one  color  to  another.  It  is  obvious  that  the 
varieties  differ  in  color  alone,  and  are  alike  in  form,  odor,  and 
nectar.  Under  these  conditions  bees  quickly  learn  that  it  is  for 
their  advantage  to  ignore  differences  in  hue. 

But  the  flowers  of  many  closely  allied  species  are  so  similar 
that  they  puzzle  even  the  highest  authorities  in  taxonomy; 
and  Asa  Gray  writes  in  one  of  his  letters  that  the  asters  threat- 
ened to  reduce  him  to  blank  despair.  In  such  cases  honey-bees 
cease  to  adhere  strictly  to  a  single  species,  and  visit  indiscrim- 
inately the  different  kinds  of  buttercups,  spiraeas,  and  golden- 
rods.  I  have  also  often  seen  bumblebees  pass  from  one  species 
of  goldenrod  to  another,  and  even  back  and  forth  between 
goldenrods  and  asters.  Occasionally  I  have  seen  them  pass 
between  very  different  forms  of  flowers,  as  from  the  sunflower 

92 


Fig.  47.     Bushy  Goldenrod.     Solidago  graminifolia 


THE  FLOWER  AND  THE  BEE 

to  the  scarlet  runner,  or  from  the  goldenrod  to  the  purple 
vervain  {Verbena  hastata). 

On  the  other  hand,  the  honey-bee  often  displays  a  remark- 
able power  of  distinguishing  between  closely  allied  species  even 
when  they  are  of  the  same  color.  One  of  the  common  golden- 
rods  {Solidago  graminifolia)  has  its  heads  or  capitula  arranged' in 
crowded,  flat-topped  corymbs.  (Fig.  47.)  Another  common 
variety  (S.  rugosa)  has  the  inflorescence  panicled.  (Fig.  48.) 
In  an  upland  pasture  these  two  species  were  found  growing  to- 
gether, the  panicled  form  being  much  the  more  abundant. 
Honey-bees,  the  only  insects  present,  showed  a  marked  pref- 
erence for  8.  graminifolia,  although  occasionally  they  passed 
over  to  the  other  species.  They  were  repeatedly  seen  to  leave 
S.  graminifolia,  and  after  flying  about,  but  not  resting  on  the 
flowers  of  S.  rugosa,  return  to  the  plants  they  had  left  only  a 
few  moments  before.  In  another  instance  a  bee  was  seen  to 
wind  its  way  among  the  plants  of  the  latter  species  until  it 
found  an  isolated  plant  of  S.  graminifolia.  A  plant  of  each 
of  the  above  species  was  bent  over  so  that  the  blossoms  were 
intermingled,  appearing  as  a  single  cluster;  a  honey-bee  rested 
on  8.  graminifolia,  and  it  seemed  very  probable  that  it  would 
pass  over  to  the  flowers  of  S.  rugosa,  but  such  was  not  the  case, 
for  presently  it  flew  away  to  another  plant  of  the  former.  The 
behavior  of  these  bees  in  their  endeavors  to  adhere  to  a  single 
species  was  thus  attended  both  by  loss  of  time  and  repeated 
visits  to  the  same  blossoms. 

On  another  occasion  the  whitish  or  cream-colored  inflores- 
cence of  Solidago  bicolor,  our  one  non-yellow  species  of  golden- 
rod  (Fig.  49),  was  observed  to  be  very  frequently  visited  by  the 
males  of  Bombus  ternarius,  while  the  yellow-flowered  golden- 
rods  in  the  vicinity  were  entirely  neglected.  By  holding  yel- 
low-flowered  clusters   directly   in   their   way  I  repeatedly  in- 


THE  GATHERING  OF  THE  NECTAR 

duced  the  bumblebees  to  leave  S.  bicolor;   but  they  quickly 
perceived  that  they  had  passed  to  a  different  flower,  and  in- 


FiG.  48.     Tall,  Hairy  Goldenrod.     Solidago  rugosa 
Yields  a  heavy  golden-yellow  honey 


variably  after  a  few  seconds  or  sometimes  instantly  returned  to 
the  cream-colored  species.  They  were  probably  influenced  by 
the  greater  supply  of  nectar  in  the  flowers  of  S.  bicolor,  for  the 

95 


THE   FLOWER   AND   THE   BEE 

plants  were  growing  on  burned  land  and  were  of  larger  size 
than  usual. 

Butterflies  are  much  less  particular  in  their  visits,  and  I 
have  frequently  seen  the  silver-winged  butterfly  {Argynnis 
aphrodite)  fly  back  and  forth  between  the  flowers  of  the  com- 
mon elecampane  {Inula  Helenium)  and  the  Canada  thistle. 
This  yellowish-red  butterfly  was  flitting  about  upon  the  large 
yellow  flower-heads  of  Inula,  for  which  it  showed  a  decided  pref- 
erence to  the  purple  flowers  of  the  thistle.  The  white  cabbage- 
butterfly,  on  the  contrary,  which  was  common  on  the  thistle- 
bloom,  confined  its  visits  chiefly  to  that  species.  This  singular 
behavior  must  have  been  determined  by  other  causes  than  the 
color  of  the  floAvers.  In  illustration  of  the  irregular  habits  of 
flies  in  visiting  flowers,  I  may  mention  that  I  have  seen  the 
syrphid  fly  Mesograpta  gerniinata  pass  from  the  water-horehound 
{Lycopus  europwus)  to  the  tear-thumb  {Polygonum  sagitfatum) 
and  thence  to  the  blossoms  of  the  smaller  willow-herb  {Epilo- 
bium  molle),  where  its  career  ended  in  my  collecting-net. 

When  the  nectar  is  deeply  concealed  in  irregular  flowers  or 
long  nectaries,  as  in  the  larkspur,  clover,  columbine,  fly-honey- 
suckle, and  skullcap,  a  much  greater  amount  of  time  is  required 
to  gather  it  than  when  it  is  fully  exposed.  Such  flowers  are 
chiefly  adapted  to  the  skilful,  long-tongued  bees,  while  beetles, 
flies,  wasps,  and  many  other  insects  are  either  unable  to  find- 
it  or  have  a  tongue  too  short  to  reach  it.  In  order  to  obtain  the 
nectar  more  easily  than  by  entering  the  flowers  in  the  legitimate 
way  certain  bumblebees  have  formed  the  curious  habit  of 
biting  holes  in  the  nectaries  or  corolla- tubes.  The  holes  are 
made  by  the  laciniae  or  lance-shaped  ends  of  the  maxillae. 
The  maxillae,  which  are  the  second  pair  of  jaws  and  are  situated 
just  below  the  mandibles,  are  composed  of  two  joints,  a  basal 
part  called  the  stipe,  and  a  terminal  acutely  pointed  blade  or 

96 


Fig.  49.     Cream-Colored  Goldenrod.     Solidago  hicolor 


THE   FLOWER  AND   THE   BEE 

lacinia.  When  these  two  sharp  points  are  moved  back  and 
forth  on  the  outer  side  of  a  nectary  they  may  puncture  it,  mak- 
ing either  a  single  sht  or  two  small  holes  side  by  side. 

The  fly-honeysuckle  {Lonicera  ciliata)  is  a  graceful,  slender 
shrub,  which  blooms  in  northern  woodlands  during  the  last 
weeks  in  May.  The  flower-stalk  bears  at  its  summit  two 
pendulous,  yellowish-green  flowers,  which  are  tubular  and  half 
an  inch  in  length.  The  nectar  is  secreted  and  lodged  at  the 
base  of  this  tube,  where  it  can  be  reached  by  the  long  tongues 
of  bumblebees,  by  which  the  flowers  are  pollinated.  The  fe- 
male of  Bomhus  vagans  was  often  observed  stealing  the  sweet 
secretions  through  holes  in  the  buds.  Sometimes  the  perfora- 
tion was  near  the  apex,  but  usually  it  was  near  the  base  of  the 
tube,  and  in  one  instance  I  found  the  corolla  nearly  circumcised 
and  held  only  by  a  few  threads.     (Fig.  50.) 

Bumblebees  also  puncture  at  the  apex  (usually  on  the  under- 
side) the  buds  of  the  common  skullcap  {Scutellaria  galericulata) , 
even  when  they  are  quite  immature.  The  flowers  are  bilabiate, 
or  two-lipped.  In  two  instances  I  observed  a  narrow  slit  on 
the  under-side  of  the  corolla-tube,  and  in  a  third  case  the 
whole  upper  portion  of  the  tube  was  cut  away,  leaving  the  lips 
suspended  by  a  mere  thread.  Hundreds  of  spurs  of  the  wild 
balsam  {Impatiens  hiflora)  are  perforated  on  the  under-side; 
sometimes  there  are  several  holes,  in  other  cases  a  single  slit. 
After  the  punctures  are  once  made  honey-bees  rob  the  flowers 
as  well  as  bumblebees,  making  about  ten  visits  per  minute. 

The  garden-columbines  secrete  nectar  very  plentifully.  If  a 
flower  of  the  white  variety  be  held  so  that  the  light  shines 
through  its  translucent  tissue,  the  nectar  may  be  seen  filling  a 
tenth  of  an  inch  of  the  hollow  spurs  or  nectaries.  Both  the 
purple  and  white  varieties  are  punctured  by  bumblebees. 
Mueller  observed  a  bumblebee,  after  a  fruitless  endeavor  to 


THE  GATHERING  OF  THE  NECTAR 

obtain  the  nectar,  bite  a  hole  in  the  spur;  and  afterward  it 
punctured  the  flowers  visited  without  any  prehminary  delay. 
I  have  noticed  three  distinct  incisions,  one  above  the  other, 
on  a  petal  of  this  plant.     The  first  was  over  half  an  inch  from 


Fig.  50.     Fly-Honeysuckle.     Lonicera  ciliata 

A  bumblebee-flower;  in  their  haste  to  obtain  the  nectar  bumblebees 
often  puncture  the  corolla 

the  tip  of  the  spur,  well  up  on  the  expanded  part  of  the  tube; 
the  second  was  lower  down,  and  the  third  still  nearer  the  tip. 
Apparently  the  upper  puncture  was  too  far  distant  to  permit 
the  tongue  of  the  bee  to  reach  the  nectar,  and  to  rectify  this 
mistake  the  other  holes  were  made  lower  down. 

99 


THE   FLOWER  AND  THE  BEE 

Although  honey-bees  freely  rob  the  nectaries  after  they  have 
been  punctured  by  bumblebees,  they  are  probably  not  able 
themselves  to  bite  holes  in  them.  On  August  14,  1909,  the 
vines  of  the  scarlet  runner  in  my  garden  were  a  blaze  of  glory. 
Honey-bees  and  bumblebees  were  constantly  coming  and  go- 
ing, but  not  one  of  them  visited  the  flowers  in  the  normal  way. 
There  was  a  hole  on  the  under-side  of  every  nectary;  and  the 
bees  went  directly  to  these  holes,  out  of  which  they  easily  sucked 
the  nectar.  The  punctures  were  all  on  the  left-hand  side,  which 
may  be  explained  by  the  fact  that  the  larger  bees  almost  in- 
variably alight  on  the  left  wing,  for  the  reason  that  the  spirally 
coiled  carina  closes  the  entrance  beneath  the  standard  on  the 
right-hand  side. 

In  the  spring  of  the  following  year,  1910,  I  planted  5  hills 
of  the  scarlet  runner  bean  at  a  distance  of  about  50  feet  from 
my  apiary.  By  the  last  of  July  it  was  in  bloom  and  presented 
a  most  attractive  appearance.  I  examined  20  racemes,  but  not 
a  flower  was  punctured.  Throughout  the  season  I  kept  the 
flowers  under  close  surveillance,  but  with  the  same  result — 
none  of  them  were  perforated.  What  was  the  cause  of  this 
result,  which  was  directly  opposite  to  that  observed  the  previ- 
ous season  ?  For  some  reason,  perhaps  the  absence  of  any  nests 
in  the  vicinity,  in  1910,  during  the  entire  blooming-period  of 
the  scarlet  runner,  I  saw  not  a  single  specimen  of  Bombus  terri- 
cola  in  my  garden,  the  species  of  bumblebee  so  common  on  the 
flowers  the  preceeding  season.  The  honey-bees  from  the  neigh- 
boring hives  were  constantly  flying  over  the  garden,  but  they 
did  not  puncture  the  flowers,  doubtless  because  they  were  not 
able  to  do  so.  The  perforations  of  the  previous  season  appear 
thus  to  have  been  made  wholly  by  bumblebees.       (Fig.  51.) 

It  has  frequently  been  asserted  that  honey-bees  puncture 
ripe  grapes,  but  this  is  undoubtedly  an  error.     The  punctures 

100 


Fig.  51.     Scarlet  Runner.     Phaseolus  nuiltifloms 

A  bumblebee-flower,  iu  which  bumblebees  sometimes  bite  holes  in  order  to  obtain  the  nectar 

more  easily 


THE  FLOWER  AND  THE  BEE 

are  invariably  made  by  birds  or  some  other  agency  and  are 
subsequently  used  by  the  bees  for  sucking  out  the  contents  of 
the  fruit.  Clusters  of  whole  ripe  grapes  placed  in  hives  among 
starving  bees  remained  untouched,  but  if  they  were  pricked 
with  a  pin  their  contents  were  at  once  extracted.  Honey-bees, 
however,  do  bore  into  soft,  succulent  tissue  for  sap.  In  the 
common  laburnum  there  is  a  round,  fleshy  swelling  at  the  base 
of  the  standard,  which  bees  and  butterflies  pierce  for  the 
abundant  sap.  There  are  several  species  of  orchis  (0.  morio 
and  0.  maculata)  which  are  nectarless  and  which  Sprengel 
called  "sham-nectar  producers."  The  inner  membrane  of  the 
floral  tube  is  a  very  delicate  structure  and  beneath  it  there  is 
a  copious  supply  of  fluid.  Mueller  saw  a  honey-bee  pierce 
this  tissue  a  number  of  times.  Bees  also  probe  with  the  points 
of  their  maxillae  pollen-flowers  like  the  Anemone.  Moths  and 
butterflies  are  also  able  to  puncture  plant-tissues  to  some  extent. 
Darwin  tells  of  a  moth  in  Queensland,  Australia,  which  with 
its  wonderful  proboscis  can  bore  through  the  thick  rind  of  an 
orange.  At  the  Cape  of  Good  Hope  both  moths  and  butter- 
flies are  said  to  do  much  injury  to  peaches  and  plums  by  punc- 
turing the  unbroken  skins. 

Bumblebees  are  known  to  bite  holes  in  more  than  300  species 
of  flowers  and  rob  them  of  nectar.  Several  of  these  often  fail 
to  produce  seed.  A  few  of  the  more  common  forms  robbed  by 
bees,  besides  those  already  mentioned,  are  red  clover,  locust, 
Dicentra,  Corydalis,  dead-nettle,  larkspur,  aconite,  and  vetch. 
Wasps  have  also  been  observed  to  bite  holes  in  flowers. 

Bees  are  frequently  described  as  roaming  about  among  flowers 
leading  a  joyous,  care-free  existence;  but  they  often  meet  a 
terrible  fate  and  are  seized  by  a  monster  as  remorseless  as  the 
fabled  Scylla  of  ancient  mythology.  The  Thomisidw,  or  crab- 
spiders,  have  acquired  the  habit  of  living  among  flowers  for  the 

102 


THE  GATHERING  OF  THE  NECTAR 

purpose  of  preying  on  the  insect  visitors.     They  usually  lurk 
in  dense  clusters  of  small  flowers,  like  the  inflorescence  of  the 


Fig.  52.     Large  Insects  Captured  by  Crab-Spiders 

I,  Butterfly,  Papilio  asterias,  captured  by  crab-spider,  Misumena  vatia,  2.   3,  dragon-fly, 
i'elithemis  eponina,  killed  by  crab-spider,  M.  vatia,  -l 


sumach,  meadow-sweet,  elderberry,  Viburnum,  cornel,  and  the 
bristly  sarsaparilla,  although  they  are  also  found  on  large  in- 
dividual flowers  like  the  rose.     The  commonest  species  of  the 

103 


THE  FLOWER  AND  THE   BEE 

family  is  Misumena  vatia,  a  white  spider  with  a  crimson  stripe 
on  each  side  of  the  abdomen,  which  easily  escapes  notice  until 
a  dead  insect  is  seen  lying  upon  the  surface  of  the  inflorescence. 
Another  species  (M.  asperata)  has  red  markings,  and  sometimes 
exactly  resembles  the  sorrel  {Rumex  Acetosella). 

Misumena  does  not  spin  a  web,  but  conceals  itself  among  the 
flowers  and  pounces  upon  its  unsuspecting  prey  while  it  is 
collecting  pollen  or  nectar.  One  morning  in  July  I  had  the 
opportunity  to  observe  the  capture  of  a  bumblebee  gathering 
pollen  on  a  wild  rose.  My  attention  was  for  a  moment  di- 
verted, but  was  again  recalled  by  the  loud  buzzing  of  the  bee. 
The  spider  had  leaped  upon  its  back  and  grasped  it  with  its 
mandibles  just  behind  the  head.  At  first  the  bumblebee  strug- 
gled violently,  but  so  virulent  was  the  poison  that  its  move- 
ments speedily  ceased  entirely.  The  spider  then  dragged  it 
over  the  edge  of  the  flower  to  the  leaves  beneath,  where  it  dined 
at  leisure. 

The  temerity  and  success  with  which  the  TJiomisidoB  attack 
large  butterflies  or  dragon-flies,  or  stinging  insects,  as  wasps, 
bumblebees,  and  honey-bees,  is  astonishing.  Honey-bees  are 
often  captured,  and  large  flies  belonging  to  the  genera  Archytas 
and  Theriopledes  and  rarely  the  wasp  Vespa  germanica.  It  is 
difficult  to  understand  why  the  spiders  are  not  carried  away 
by  such  strong-winged  insects  as  the  dragon-fly  and  the  large 
butterfly  Papilio  asterias,  which  so  greatly  surpass  them  in 
size  and  strength.     (Fig.  52.) 

The  habit  of  resorting  to  flowers  to  capture  anthophilous 
insects  and  the  protective  resemblance  of  coloration  must  have 
been  acquired  by  the  crab-spiders  in  comparatively  recent 
times — that  is,  since  the  evolution  of  flowers  and  the  develop- 
ment of  anthophily  among  insects.  The  new  habit  would 
seem  to  be  the  result  of  observation  and  experience. 

104 


CHAPTER  VII 
BEES  WHICH  VISIT  ONLY  ONE  KIND  OF  FLOWER 

ONE  warm  afternoon  on  the  20th  of  July  I  was  collect- 
ing insects  from  a  boat  on  the  Medomac  River.  A 
thunder-shower  was  coming  up  in  the  northwest.  The 
air  was  very  still  and  in  that  peculiar  condition  which  pre- 
cedes an  electric  storm.  At  such  times  insects  are  very  sluggish 
and  seek  shelter  against  the  approaching  tempest.  The  silence 
was  broken  only  by  the  rumbling  peals  of  the  distant  thunder, 
following  the  bright  flashes  of  lightning,  which  illumined  the 
dark  thunder-heads  of  the  advancing  clouds.  It  became 
necessary  for  me  to  hasten  homeward.  To  my  surprise  I 
noticed  on  almost  every  one  of  the  violet-blue  spikes  of  the 
pickerel-weed  {Pontederia  cordata),  a  species  of  water-hyacinth, 
which  in  countless  numbers  fringed  the  winding  stream  on 
both  sides,  one  to  several  small  bees.  They  had  crept  within 
the  bilabiate  flowers  as  far  as  possible,  and  were  evidently  in- 
tending to  await  there  the  passing  of  the  storm.  They  were  so 
inactive  that  no  net  was  required,  and  I  could  easily  knock 
them  off  into  the  cyanide  jar.  I  collected  about  40  specimens 
and  could  have  easily  collected  hundreds.  This  phenomenon 
has  never  been  repeated  to  my  knowledge. 

On  examination  the  bee  proved  to  be  HaUcioides  novce-anglicB, 
or  the  pickerel-weed  bee.  Every  season  when  the  pickerel- 
weed  is  in  bloom  I  find  both  sexes  of  this  bee  on  its  flowers, 
and  although  I  have  carefully  observed  the  visitors  to  many 
other  plants  in  this  locality,  I  have  never  met  with  it  elsewhere. 
Apparently  in  this  region  it  never  visits  any  other  flower — it 

105 


THE  FLOWER  AND   THE  BEE 

IS  a  monotropic  bee.  When  a  species  of  bee  restricts  its  visits 
chiefly  to  one  kind  of  flower  it  is  termed  a  monotropic  bee;  or 
to  a  few  aUied  kinds  of  flowers  an  oHgo tropic  bee;  but  if  it  visits 
many  flowers  a  polytropic  bee.  These  terms  were  first  pro- 
posed by  Loew,  and  signify:  adapted  to  one,  few,  or  many 
flowers. 

It  is  impossible  not  to  feel  some  curiosity  as  to  why  this  little 
bee  restricts  its  visits  to  the  inflorescence  of  the  pickerel-weed. 
Notice  that  it  flies  only  at  the  season  of  the  year  when  this 
aquatic  plant  is  in  bloom,  and  that  it  finds  within  the  perianth 
both  food  and  shelter.  Very  likely  its  nests  are  built  not  far 
away.  The  flowers  of  the  pickerel-weed  strongly  attract  in- 
sects by  their  great  numbers,  bright  hues,  pleasant  fragrance 
and  abundant  nectar  and  pollen,  and  consequently  are  sought 
out  by  many  bees,  flies,  and  butterflies.  (Fig.  53.)  Bumble- 
bees especially  delight  in  these  blossoms,  which  they  visit  with 
astonishing  rapidity — Bomhns  vagans  making  about  70  visits  per 
minute.  On  the  middle  lobe  of  the  upper  lip  there  are  two 
bright-yellow  spots,  which  tell  of  the  presence  and  guide  to 
the  exact  location  of  the  nectar  concealed  within  the  tube 
of  the  perianth.  When  the  pickerel-weed  bee  makes  its  appear- 
ance, about  the  middle  of  July,  there  is  no  other  flower  in  south- 
ern Maine  which  can  offer  it  so  many  inducements  as  the  pick- 
erel-weed. But  let  us  look  further  and  see  if  there  are  any 
other  bees  which  behave  in  a  similar  manner. 

In  the  quiet  bays  of  the  river,  floating  upon  the  surface  of 
the  water,  bloom  the  yellow  water-lilies  {Nymphcea  advena). 
(Fig.  54.) 

"Again  the  wild  cow-lily  floats 
Her  golden-freighted,  tented  boats, 
O'ershadowed  by  the  whispering  reed. 
And  purple  plumes  of  pickerel-weed." 
106 


Fig.  53.     Pickerel- Weed.     Pontederia  cordata 
In  New  England  a  small  bee,  Halidoides  nova-angli(F,  never  visits  any  other  flower 


THE   FLOWER  AND   THE   BEE 

The  flower  is  securely  anchored  to  the  bottom  of  the  stream 
by  a  long  stem.  At  first  the  opening  in  the  bud  is  no  larger 
than  a  bee's  body,  and  the  chamber  within  offers  a  dry  and 
snug  shelter  amid  the  waves.  It  may  be  truly  called  a  haven  of 
refuge.  Directly  below  the  entrance  is  a  broad,  many-rayed, 
crown-shaped  stigma,  as  in  the  poppy.  The  petals  are  thick, 
wedge-shaped  bodies  which  are  orange-yellow  on  the  outer 
side  near  the  top,  where  they  freely  secrete  nectar.  Under  a 
microscope  both  large  and  minute  drops  can  readily  be  seen. 
The  stamens  are  indefinite  in  number;  and  revelling  in  the 
pollen,  their  bodies  completely  covered,  there  is  a  large  and 
lively  company  of  small  flies  called  Hilar  a  atra.  Less  common 
are  two  beetles,  Donacia  piscatrix  and  Donacia  riifa;  but  what 
chiefly  interests  us  is  a  small  bee,  Halictus  nelumbonis,  or  the 
water-lily  bee.  This  bee  in  this  locality  is  never  found  on 
any  other  flower,  but  elsewhere  it  is  met  with  on  other  species 
of  the  water-lily  family,  or  NymphoBacece.  Since,  however,  it 
confines  its  visits  to  the  water-lily  family  it  is  an  oligotropic 
bee,  and  the  only  species  of  the  great  genus  Halictus  that  is 
known  to  behave  in  this  way. 

But  in  Andrena  this  is  a  common  phenomenon;  for  instance, 
in  Washington  County,  Wis.,  according  to  Graenicher,  24  of 
the  47  indigenous  species  of  Andrena  are  oligotropic.  This  is 
the  largest  genus  of  North  American  bees.  They  are  some- 
times called  ground-bees,  since  they  build  branched  tunnels 
8  or  10  inches  deep  in  the  soil  of  sandy  pastures  and  hillsides. 
A  part  of  the  species  are  vernal  or  fly  in  springtime,  while  a 
part  are  autumnal  and  fly  only  in  autumn.  They  provision 
their  cells  with  balls  of  "bee-bread,"  about  the  size  of  a  garden- 
pea,  composed  of  pollen  moistened  w^ith  nectar.  An  egg  is 
laid  on  the  top  of  the  mass  of  bee-bread,  and  the  cell  is  then 
closed. 

108 


Fig.  54.     Yellow  Water-Lily.     Nymphcea  advena 
Largely  pollinated  by  small  flies,  Hilara  atra 


THE   FLOWER   AND   THE  BEE 

The  bright-yellow  staminate  aments  of  the  pussy-willow 
(Salix  discolor)  (Fig.  55)  are  great  favorites  of  vernal  species 
of  Andrena,  whence  Smith  calls  them  "harbingers  of  spring." 
The  pussy-willows  bloom  in  northern  New  England  during  the 
latter  part  of  April,  and  their  bright-yellow  aments  are  very 
pleasing  objects  in  the  cold,  gray  landscape.  They  are  very 
attractive  to  a  varied  company  of  insects,  as  honey-bees,  bum- 
blebees, flies,  butterflies,  and  beetles.  It  is  a  busy  scene  and 
one  which  the  naturalist  can  never  tire  of  watching;  but  it  is 
not  one  of  unmixed  happiness,  for  little  tragedies  take  place 
before  our  eyes.  Among  those  which  come  to  sip  the  nectar 
are  little  dance-flies  (Empididcp),  and  not  infrequently  they 
are  seized  and  carried  away  bodily  by  black  robber-ants  which 
roam  everywhere.  Honey-bees  and  many  species  of  Andrena 
come  in  great  numbers  to  procure  pollen  for  brood-rearing.  A 
part  of  the  andrenid  bees  gather  only  a  portion  of  the  pollen 
they  require  from  the  willows  and  the  balance  from  the  maples, 
plums,  cornels,  and  Viburnums;  but  there  are  four  species 
(A.  illinoiensis,  A.  maricF,  A.  erythrogaster,  and  A.  moesta), 
which  get  their  whole  supply  from  this  genus  of  plants.  Of 
the  autumnal  flying  species  of  Andrena  there  are  five  {A.  cana- 
densis, A.  nubecida,  .1.  solidaginis,  A.  hirticincta,  and  A.  asteris), 
which  I  have  collected  only  on  the  flowers  of  the  Compositce,  or 
aster  family;  and  four  of  these  bees  confine  their  visits  very 
largely  to  the  goldenrods.  In  both  Salix  and  Solidago  the  in- 
florescence offers  an  ample  supply  of  nectar  and  pollen,  and 
there  is  little  temptation  for  andrenid  bees  to  go  elsewhere, 
when  their  time  of  flight  coincides  with  the  period  of  blooming 
of  these  two  genera. 

But  in  other  localities  Andrena  erigenioe  is  reported  to  be  a 
monotropic  visitor  of  the  spring-beauty  {Claytonia  virginica), 
and  Andrena   violce  of  the   violet   (Viola  cucullata),  Andrena 

110 


V    , 


Fig.  55.     Pussy-Willow.     Salix  discolor 

In  New  England  four  species  of  ground-bees  (Andretia)  never  visit  any  flowers  except  those 
of  the  willows.     A,  staminate  catkins;  B,  pistillate  catkins 


THE   FLOWER  AND   THE  BEE 

geranii  maculati  of  the  wild  geranium  {Geranium  maculatnm) , 
Andrena  fragariana  of  the  strawberry  {Fragaria  virginica)^ 
and  Andrena  parnassice  of  Parnassia  caroliniana.  It  is  not  so 
easy  to  explain  the  behavior  of  these  latter  bees.  It  seems 
very  remarkable  that  they  should  restrict  their  visits  so  closely 
to  the  flowers  mentioned. 

Macropis  ciliata,  or  the  loosestrife-bee,  usually  gets  its  pollen 
from  the  flowers  of  the  common  loosestrife  {Lysimachia  vulgaris) 
(Fig.  97) ;  but  it  visits  other  flowers  for  nectar  with  which  to 
moisten  the  pollen,  since  the  loosestrife  is  nectarless.  Many 
species  of  Panurginus  are  taken  only  on  the  inflorescence  of  the 
Composit(F. 

But  the  habit  of  visiting  only  one  kind  of  flower  is,  perhaps, 
better  illustrated  by  Perdita  than  by  any  other  genus  of  bees. 
This  large  genus  of  bees  is  confined  to  North  America  and  in- 
cludes not  far  from  150  described  species  and  varieties,  most 
common  in  the  arid  regions  of  New  Mexico.  In  Maine 
Perdita  octomacidata  is  found  almost  exclusively  on  the  panicles 
of  Solidago  juncea,  the  earliest  blooming  of  the  goldenrods 
(Fig.  56),  and  only  very  rarely  is  met  with  on  any  other  species 
of  Solidago.  In  New  Mexico  two  species  of  Perdita  are  found 
on  the  willows,  Perdita  zehrata  visits  only  Cleome  serndata, 
Perdita  crotonis  visits  Croton  texensis,  Perdita  alhipennis  visits 
Helianthus  annuus  (sunflower),  and  Perdita  senecionis  visits 
Senecio  Douglasii.  "It  may  be  laid  down  as  a  rule,"  says 
Cockerell,  "that  each  species  of  Perdita  visits  normally  but 
one  species  of  flower,  but  occasionally  specimens  may  be  found 
on  flowers  to  which  normally  they  do  not  belong."  But  in 
many  instances  several  species  of  Perdita  frequent  the  same 
flower. 

Many  species  of  CoUetes,  Epeolus,  and  Melissodes  visit  almost 
exclusively  the  flowers  of  the  Compositce,  as  the  thistles,  golden- 

112 


Fig.  56.     Early  Goldenrod.     Solidago  juncea 


,    THE  FLOWER  AND  THE  BEE 

rods,  and  asters.  Xenoglossa  pruinosa  confines  itself  to  Cu- 
curbita  Pepo,  or  the  common  field-pumpkin;  while  Megachile 
campanulcBy  one  of  the  leaf-cutting  bees,  is  a  monotropic  visitor 
of  the  bellflower  Campanula  americana.  Many  other  instances 
are  recorded,  and  many  more  will  no  doubt  be  discovered  when 
our  bee  fauna  is  better  known. 

This  is  certainly  a  very  singular  habit  on  the  part  of  bees, 
and  one  which  few  would  be  likely  to  foresee.  On  the  con- 
trary, it  is  generally  supposed  that  bees  fly  about  sipping  sweets 
indiscriminately,  as  they  are  so  commonly  represented  by  the 
poets. 

"He  woos  the  Poppy  and  weds  the  Peach, 
Inveigles  Daffodilly, 
And  then  like  a  tramp  abandons  each 
For  the  gorgeous  Canada  Lily." 

It  is  really  getting  unsafe  for  poets  to  write  about  Nature  in 
their  old  haphazard  way,  trusting  chiefly  to  their  imagination 
as  a  guide.  Fancy  can  supply  nothing  half  so  wonderful  as 
the  true  facts  about  flowers  and  insects.  Let  us  consider  what 
theories  naturalists  have  advanced  to  explain  this  curious 
habit. 

In  Kerner's  day  only  a  few  oligotropic  bees  were  known, 
and  he  believed  that  they  gave  the  preference  to  certain  flowers 
because  they  found  their  odor  so  highly  attractive.  But  it  is 
incredible  that  so  many  bees  should  be  dominated  in  their  flight 
to  such  an  extent  by  various  floral  odors,  and  besides  they  not 
infrequently  visit  several  flowers  which  differ  in  scent.  No 
doubt,  though,  bees  have  their  preferences  in  odors  and  nectars, 
and  probably  they  prefer  pollen  that  has  a  roughened  or  spined 
surface  to  that  which  is  smooth. 

Another  explanation  claims  that  the  bee  fauna  is  as  large  as 
the  flora  will  support  and  that  female  oligotropic  bees  have 

114 


BEES  WHICH   VISIT  ONLY  ONE  KIND  OF  FLOWER 

adopted  this  method  of  visiting  flowers  to  avoid  competition 
in  gathering  pollen  for  brood-rearing.  But  this  is  not  the  fact 
and  it  can  be  shown  that  only  a  part  of  the  available  flower-food 
is  gathered  by  bees.  The  commonness  of  an  insect  species 
does  not  depend  alone  on  the  quantity  of  food  obtainable,  e.  g.y 
occasionally  the  forest-caterpillar  {Heterocamya  guttivitta), 
which  feeds  on  the  leaves  of  deciduous  trees,  appears  in  count- 
less numbers,  defoliating  acres  of  the  woodlands  and  apparently 
threatening  the  entire  destruction  of  the  hardwood  forest; 
but  it  speedily  disappears  again  and  becomes  so  rare  that  its 
presence  is  unnoticed.  The  size  of  the  bee  fauna  is  likewise 
limited  by  other  factors  than  the  food  supply,  the  most  im- 
portant being  insect  parasites  which  destroy  annually  vast 
numbers  of  bee  larvae. 

It  is  desirable  to  consider  a  few  specific  instances  where  there 
is  unquestionable  evidence  of  a  surplus  of  flower-food.  In 
Riverside  County,  Cal.,  the  orange-bloom  secretes  nectar  so 
freely  that  it  drips  upon  the  clothing  of  the  pruners,  and  at 
the  end  of  a  day's  cultivating  in  the  groves  it  is  necessary  to 
wash  the  horses  and  harnesses.  Large  quantities  are  lost  each 
year  for  want  of  bees  to  collect  it.  Hundreds  of  acres  of  the 
sandy,  coastal  plain  of  Georgia  are  covered  with  the  bushes  of 
the  common  gall-berry  {Ilex  glabra).  It  remains  in  bloom  for 
about  a  month.  The  secretion  of  nectar  is  constant  and  but  little 
affected  by  the  weather;  but  this  sea  of  flowers  is  not  frequently 
visited  by  insects.  Immense  quantities  of  fine  honey  are  lost 
annually  because  there  are  no  bees  to  gather  it;  furthermore,  it 
is  not  easy  to  overstock  a  gall-berry  region  with  the  domestic 
bee,  and  in  one  instance  362  colonies  did  nearly  as  well  as  100 
previously.  The  production  of  honey  in  Iowa  is  placed  at  ten 
to  twelve  million  pounds  annually ;  but  according  to  a  conserva- 
tive estimate  by  Iowa  apiarists  of  great  experience,  it  is  possible 

115 


THE   FLOWER   AND   THE   BEE 

to  produce  in  that  State  in  a  single  year  60,000,000  pounds. 
The  average  moisture  content  of  honey  is  17.59  per  cent, 
while  that  of  nectar  is  not  far  from  75  per  cent,  so  that  the  weight 
of  the  nectar  would  exceed  that  of  the  honey  fourfold.  This 
estimate,  of  course,  does  not  take  into  consideration  the  nectar 
consumed  by  anthophilous  insects  other  than  the  honey-bee. 
If  a  region  were  already  stocked  to  its  fullest  capacity  with 
bees,  it  is  clear  that  it  would  be  impossible  to  establish  large 
apiaries  containing  millions  of  bees,  storing  twenty  or  more 
tons  of  honey,  consuming,  perhaps,  twice  as  much  more,  and 
requiring  enormous  quantities  of  pollen  for  brood-rearing.  It 
will  be  remembered  that  the  honey-bee  does  not  usually  fly 
more  than  two  miles  from  the  apiary.* 

It  would  be  easy  to  multiply  examples  in  the  case  of  buck- 
wheat, basswood,  tupelo,  raspberry  (Fig.  57),  heart 's-ease,  and 
goldenrod,  and  the  extra-floral  nectaries  of  cotton  and  Cassia 
Chamoechrista  in  the  Southern  States.  Certain  plants,  as  Bidens 
aristosa  in  the  lowlands  of  the  Mississippi,  fairly  carpet  large 
areas  with  their  myriads  of  flowers.  The  "Big  Sawgrass"  is 
a  tract  of  land  in  Florida  covering  a  thousand  acres.  It  is  a 
wilderness  of  weeds,  a  dense  jungle  of  grass  and  flowers  with 
vast  stretches  of  nectariferous  plants,  like  boneset  and  wild 
sunflower,  yielding  honey  enough  to  keep  a  thousand  colonies 
busy  for  months;  but  as  yet  there  are  only  fifty  colonies  in  one 

*  The  question  might  be  raised  at  this  point  whether  there  are  not  too  many 
bee-keepers  ah'eady,  or  whether  tiie  ten  milHon  colonies  are  not  using  all  the 
honey  or  nectar  there  is  in  flowers.  The  facts  are,  more  nectar  goes  to  waste 
than  is  gathered.  It  has  been  estimated  that  from  50  to  80  per  cent  of  it  is 
lost  simply  because  there  are  no  bees  in  the  vicinity  to  gather  it.  It  is  at  least 
conservative,  says  Doctor  Phillips,  apicultural  expert  of  the  Department  of 
Agriculture,  in  his  book.  Beekeeping,  to  say  that  ten  times  as  much  honey 
could  be  produced  in  localities  where  there  are  now  no  bees  or  an  insufficient 
number,  as  is  now  produced.  In  other  words,  the  resources  of  this  country 
could  furnish  $200,000,000  worth  of  honey  instead  of  $20,000,000,  as  at  pre- 
sent.—E.  R.  Root,  in  A  B  C  and  X  Y  Z  of  Bee  Culture,  p.  3. 

IIG 


Fig.  57.     Wild  Raspberry.     Rubus  idmis  var.  aculeatisdmus 
Yields  nectar  very  freely,  and  is  annually  the  source  of  many  tons  of  a  delicious  white  honey 


THE  FLOWER  AND   THE  BEE 

corner.  Wliat  a  wealth  of  sweetness  going  to  waste !  Fruit- 
growers have  learned  from  experience  that  the  wild  bees  are 
wholly  insufficient  to  gather  the  pollen  and  nectar  of  extensive 
plantations  of  fruit-trees,  berr^-bushes,  and  cranberries;  and 
effective  pollination  is  secured  only  by  the  establishment  of 
apiaries  of  the  domestic  bee.  An  immense  quantity  of  pollen, 
which  can  be  used  by  bees  in  emergencies,  is  produced  by  ane- 
mophilous  plants,  as  the  AmentacecE,  elms,  grasses,  sedges, 
rushes,  and  a  variety  of  homely  weeds.  Occasionally  honey- 
bees by  thousands  do  resort  to  anemophilous  flowers  for  pollen; 
and  much  less  frequently,  because  their  necessities  are  less, 
the  solitary  bees.  Many  plants  have  probably  remained  wind- 
pollinated,  while  others  formerly  entomophilous  have  wholly, 
or  in  part,  reverted  to  self-fertilization  or  anemophily  in  the 
absence  of  sufficient  pollinators. 

If  severe  competition  did  exist  among  the  solitary  bees  for 
flower-food,  the  oligotropic  habit  would  not  be  desirable. 
It  is  not  an  advantage  for  a  bee  to  restrict  its  visits  to  one 
kind  of  flower  unless  it  is  always  certain  to  obtain  the  food 
supply  it  requires;  otherwise  it  is  clearly  at  a  disadvantage  as 
compared  with  the  poly  tropic  species.  If  severe  competition 
is  introduced  by  artificial  means,  as  by  overstocking  a  locality, 
then  the  oligotropic  bees  will  either  tend  to  disappear  or  become 
polytropic.  The  small  number  of  oligotropic  bees  reported 
from  central  Europe  is  noteworthy.  If,  however,  a  very  com- 
mon flower  yields  a  surplus  of  food  then  a  bee  with  a  period  of 
flight  nearly  coinciding  with  the  period  of  inflorescence  would 
save  time  and  labor  by  restricting  its  visits  to  this  species; 
and  since  bees  instinctively  learn  from  observation  it  would 
naturally  be  expected  that  the  oligotropic  habit  would  be 
formed.  According  to  the  theory  proposed  by  the  writer 
certain  bees  have  become  oligotropic  because  of  the  direct 
advantage  gained,  combined  with  a  short  term  of  flight,  or  a 

118 


BEES  WHICH  VISIT  ONLY  ONE  KIND  OF  FLOWER 

flight  synchronous,  or  nearly  so,  with  the  period  of  inflorescence 
of  the  plant  to  which  they  restricted  their  visits.  This  theory 
offers  an  explanation  of  the  rise  of  oligotropism  by  the  observa- 
tion of  existing  conditions.  There  may  be,  and  often  are,  acces- 
sory factors,  as  small  size,  time  of  flight,  length  of  flight,  weak 
flight,  vicinity  of  nests,  and  the  number  of  bees. 

The  relation  of  the  domestic  bee  to  various  flowers  affords 
an  ever-present  illustration  of  the  way  in  which  the  oligotropic 
habit  might  arise  in  the  case  of  a  bee  wifh  a  short  term  of  flight. 
While  the  basswood  and  white  clover  are  in  bloom  the  honey- 
bee visits  these  flowers  almost  exclusively.  Again,  in  the  fall 
in  Maine  it  confines  its  attention  solely  to  the  goldenrods. 
In  California  at  times  it  collects  nectar  exclusively  from  the 
sages;  in  Michigan  from  the  willow-herb,  and  in  other  regions 
from  other  plants.  If  from  any  one  of  these  plants  it  also  ob- 
tained its  supply  of  pollen  and  was  on  the  wing  only  while  it 
was  in  bloom,  it  would  be  a  monotropic  bee  in  the  strict  sense 
of  the  word.  There  is  here  no  question  of  competition;  the 
bees  come  to  procure  the  great  abundance  of  nectar,  and  pollen 
is  gathered  at  the  same  time  as  a  matter  of  convenience.  But 
where  a  bee  flies  from  early  spring  to  late  fall  and  requires  a 
large  amount  of  stores,  it  is  evident  that  it  can  never  become 
oligotropic. 

There  can  be  no  competition  where  there  is  an  overabundance 
of  supplies.  No  other  early  blooming  flowers  yield  so  much 
pollen  and  nectar  as  the  willows.  No  other  genus  of  honey- 
plants  in  early  spring  is  so  valuable  to  the  apiarist  as  Salix. 
Honey-bees  gather  large  quantities  of  pollen,  and  in  some 
localities  are  reported  as  storing  from  8  to  15  pounds  of  honey 
per  hive  from  this  source  alone.  Four  species  of  Andrena, 
which  are  on  the  wing  for  about  a  month,  visit  the  willows  ex- 
clusively, because  during  their  comparatively  short  term  of 
flight  they  can  readily  obtain  all  the  pollen  and  nectar  they  re- 

119 


THE  FLOWER  AND   THE  BEE 

quire,  and  there  is  no  occasion  for  them  to  go  elsewhere.  There 
are  also  on  the  wing  at  the  same  time  6  species  which  are  poly- 
tropic,  but  they  all  obtain  a  part  of  their  food  supplies  from  the 
willows,  so  that  the  oligotropic  species  would  not  escape  com- 
petition with  them  if  there  was  a  scarcity  of  pollen  and  nectar. 
Their  average  time  of  flight  is  about  sixty-three  days,  or  43 
per  cent  longer  than  that  of  the  oligotropic  species,  which 
renders  it  necessary  for  them  to  obtain  a  part  of  their  pollen 
from  other  flowers  than  those  of  Salix. 

In  Milwaukee  County,  Wis.,  according  to  Graenicher,  there 
are  11  autumnal  species  of  Andrena;  and  all  of  them,  with  one 
exception,  are  oligotropic  visitors  of  the  Compositcp.  The  single 
exception  {A.  parnassice)  is  found  only  near  Whitefish  Bay, 
Lake  Michigan,  where  Parnassia  caroliniana  produces  a  great 
abundance  of  flowers.  Evidently  this  bee  gets  its  pollen  from 
these  flowers  because  they  are  very  common  in  the  one  locality 
where  it  is  known.  All  the  other  species,  10  in  number,  are 
oligotropic  to  the  CompositoB.  Many  genera  of  this  family 
are  exceedingly  common,  as  the  goldenrods,  asters,  sunflowers, 
and  thoroughworts,  and  yield  immense  quantities  of  nectar 
and  pollen.  There  are  very  strong  inducements  for  these 
bees  to  visit  these  flowers,  and  comparatively  little  for  them  to 
go  elsewhere.  In  New  England  4  species  of  Andrena  restrict 
their  visits  to  the  goldenrods,  from  which  the  honey-bees  gather 
annually  many  tons  of  honey  and  a  great  amount  of  pollen. 
Neither  the  visits  of  the  domestic  bee  nor  of  the  andrenid  bees 
are  the  result  of  competition,  l)ut  solely  of  the  advantages 
gained. 

The  majority  of  oligotropic  bees  flying  in  summer  and 
autumn,  whether  they  be  species  of  Colletes,  Andrena,  Perdita, 
Panurginus,  or  Melissodes,  visit  exclusively  the  Compositce. 
The  large  and  crowded  inflorescence  consisting  of  many  small 
flowers  which  can  be  quickly  and  easily  visited,  the  great  abun- 

120 


BEES   WHICH   VISIT   ONLY   ONE   KIND   OF  FLOWER 

dance  of  pollen  and  nectar,  and  the  commonness  and  wide 
distribution  of  many  species  are  the  factors  which  attract  these 
bees.  No  other  family  of  plants  blooming  at  the  season  offers 
equal  advantages.  The  different  genera  of  the  Composilop 
vary  greatly  in  the  length  of  the  floral  tubes,  while  in  the  genera 
of  bees  the  length  of  the  tongue  also  varies  greatly.  Thus  it  is 
the  tube  length  of  the  flower  which  is  the  factor  limiting  the 
visits  of  many  species  of  bees  to  certain  composite  genera. 
Small  bees  with  short  tongues  do  not  resort  to  the  same  flowers 
as  larger  bees  with  longer  tongues.     (Fig.  58.) 

Practically  all  of  the  species  of  Perdita  are  oligotropic. 
They  are  small  bees  with  a  short  flight.  A  part  of  the  species 
are  vernal;  but  the  majority  fly  in  late  summer  and  autumn 
and  many  visit  the  Compositcp.  The  flowers  visited  by  them 
occur  in  immense  profusion  and  include  the  best  honey -plants 
of  this  country,  as  Salix,  Solidago,  Cleome,  Prosopis,  Helianthus, 
Verbeshia,  Bidens  ari.stom,  and  Monarda  punctata.  It  is  note- 
worthy that  we  find  these  flowers  also  visited  by  oligotropic 
bees  belonging  to  other  genera.  This  behavior  on  the  part  of 
so  many  species  of  bees  is  very  similar  to  that  of  higher  forms  of 
life  when  they  gather  at  some  feeding-ground  where  there  is 
a  superabundance  of  food. 

Since  the  nest-building  bees  are  compelled  to  collect  pollen 
for  brood-rearing  they  are  naturally  more  constant  in  their 
visits  to  flowers  than  the  parasitic  bees,  which  do  not  gather 
pollen  and  require  nectar  only  for  themselves.  Nevertheless  a 
number  of  the  parasitic  bees  with  a  short  term  of  flight  visit 
wholly  or  largely  the  Compositoe  and  may  be  regarded  as  oligo- 
tropic species.  This  is  of  great  interest  since  it  is  not  claimed 
that  they  have  acquired  this  habit  as  the  result  of  competition. 

We  may  sum  up  the  matter  as  follows.  All  bees  including 
the  honey-bee  show  a  strong  tendency  in  collecting  both  nec- 
tar and  pollen  to  be  constant  to  one  species  of  flower.     This  is 

V2\ 


THE   FLOWER  AND  THE  BEE 

manifestly  for  the  advantage  of  both  insects  and  flowers.  In 
the  case  of  a  number  of  bees  flying  for  only  a  small  part  of  the 
season  this  habit  has  become  so  specialized  that  they  visit 
only  one  or  a  few  allied  species  of  flowers,  which  offer  an  abun- 
dance of  pollen  and  nectar.  As  the  honey-bee  for  a  time  re- 
stricts its  visits  to  the  white  clover,  so  in  like  manner  a  mono- 
tropic  bee  visits  but  a  single  kind  of  flower.  But  in  the  former 
case  the  bee  flies  throughout  the  whole  season;  but  in  the  latter, 
when  the  flower  fades,  the  bee's  period  of  flight  is  over. 

The  idiosyncrasies  of  bees  in  visiting  flowers  present  many 
remarkable  peculiarities,  and  undoubtedly  offer  an  attractive 
field  for  observation.  There  are  certain  bees  which,  though 
they  are  not  oligotropic,  obtain  the  larger  part  of  their  supplies 
from  comparatively  few  flowers,  as  the  plums,  thorn-bushes, 
cornels,  and  viburnums.  In  this  locality  one  of  the  leaf -cutting 
bees  {Megachile  melanophcsa)  shows  a  decided  preference  for 
the  purple  vetch  (Vicia  Cracca),  and  if  I  desired  a  specimen  I 
should  look  for  it  on  the  blossoms  of  this  plant.  Since  the 
male  bees  do  not  gather  pollen  they  may  not  visit  the  same 
flowers  as  the  females,  though  the  attraction  of  the  female  may 
largely  influence  their  course,  in  which  respect  they  exhibit 
quite  human  sentiments.  It  would,  of  course,  be  in  vain  to 
look  for  the  males  of  Bomhus  and  Halictus  on  the  flowers  of 
spring,  since  they  do  not  appear  until  midsummer.  In  the 
case  of  dioecious  plants,  or  plants  in  which  the  sexes  are  on  dif- 
ferent individuals,  the  bees  visiting  the  staminate  flow^ers  are 
more  numerous  and  are  sometimes  widely  different  from  those 
visiting  the  pistillate.  The  common  sumac  is  a  good  example. 
Indeed,  the  bees  visiting  a  flower  in  its  early  stages  may  differ 
from  those  visiting  it  in  its  later  stages.  Again  the  visitors  to 
a  flower  may  differ,  both  in  number  and  kind,  in  different  sea- 
sons. 

122 


THE  FLOWER  AND   THE  BEE 

The  depth  at  which  the  nectar  is  concealed  is  another  most 
important  factor  in  controUing  the  visits  of  bees.  In  some 
flowers  it  is  fully  exposed  on  a  flat  surface  where  it  is  accessible 
to  all  insects;  in  others  it  is  at  the  bottom  of  a  slender  tube, 
where  it  can  be  reached  only  by  the  larger  moths.  The  familiar 
fable  of  the  crane  and  the  fox  is  constantly  illustrated  among 
flowers.  As  a  matter  of  fact,  bumblebees  and  butterflies  avoid 
rotate,  flat  flowers  containing  little  nectar,  since  their  long 
tongues  do  not  permit  them  to  suck  easily  on  such  a  surface. 
On  the  other  hand,  it  would  be  useless  to  look  for  the  smaller 
bees  with  short  tongues  on  the  larkspurs  and  clovers,  for  the 
nectar  is  quite  beyond  their  reach. 

As  we  take  leave  of  the  oligotropic  bees  it  may  be  inquired 
if  there  are  any  other  insects,  which  visit  only  one  species  of 
flower.  There  are  many  others,  especially  among  butterflies 
and  moths.  The  flag-beetle  {Mononychus  vulpeculus)  passes 
its  entire  life  on  the  blue  flag  {Iris  versicolor).  This  small 
weevil  feeds  both  on  the  pollen  and  nectar,  and  sometimes 
gnaws  the  floral  leaves  badly.  The  eggs  are  laid  in  the  young 
seed-capsules,  where  the  larvse  feed  on  the  ripening  seeds. 
Both  the  adult  beetles  and  the  larvae  are  supported  at  the  ex- 
pense of  the  blue  flag.  The  legitimate  pollinators  are  bees, 
and  while  the  flag-beetle  may  rarely  effect  pollination,  it  does 
far  more  harm  than  good.  This  symbiotic  relation  is  a  benefit 
to  the  insect,  but  an  injury  to  the  plant. 

The  night-blooming  yucca,  or  Spanish  bayonet,  which  flour- 
ishes throughout  the  Southern  States,  is  pollinated  exclusively 
by  a  small  nocturnal  moth.  The  larvse  of  the  moth  live  in  the 
seed-capsule.  Thus  both  plant  and  moth  are  reciprocally 
dependent  on  each  other,  and  the  destruction  of  the  one  would 
be  followed  by  the  disappearance  of  the  other.  But  in  most 
instances  the  insect  receives  the  greater  benefit. 

124 


CHAPTER  VIII 
BUTTERFLY-FLOWERS 

FLOWERS  are  the  playground  of  butterflies,  where  all 
day  long  in  warm,  sunny  weather  they  flit  about  "like 
tickled  flowers  with  flowers."  Pirouetting  the  hours 
away  in  airy  dances  and  free  from  the  care  of  providing  for  their 
offspring,  butterflies  are  permitted  by  Nature  to  enjoy  a  greater 
amount  of  pleasure  than  is  granted  to  any  other  of  her  insect 
children.  Their  beautiful  colors  have  made  them  the  favorites 
of  collectors,  and  led  Jean  Paul  to  call  them  "the  flowers  of  the 
air."  When  they  migrate  in  vast  numbers,  as  they  occasionally 
do,  they  fill  the  air  with  clouds  of  color  comparable  to  the  un- 
broken sheets  of  bloom  displayed  by  the  mountain-laurel  and 
the  flame-colored  azalea.  The  beauty  and  brilliancy  of  the 
bird-winged  butterflies  {Ornithoptera)  in  the  oriental  tropics, 
says  Wallace,  are  indescribable;  and  the  capture  of  a  new 
species  filled  him  with  such  intense  joy  that  on  taking  it  out 
of  his  net  and  opening  its  glorious  wings,  his  heart  began  to 
beat  violently,  and  he  felt  much  more  like  fainting  than  he  had 
done  when  in  apprehension  of  immediate  death. 

In  the  forests  of  the  Amazon,  says  Bates,  brilliant-hued 
butterflies  occur  in  so  great  numbers  and  in  such  endless  diver- 
sity that  they  compensate  for  the  scarcity  of  flowers  and  are  a 
feature  in  the  physiognomy  of  the  landscape.  On  the  moist 
sand-beaches  of  the  river  vast  numbers  of  sulphur-yellow 
and  orange  butterflies  congregate  in  densely  packed  masses 
two  or  three  yards  in  circumference  and  resemble  beds  of 
yellow  crocuses ;  while  flitting  about  among  the  trees  a  butter- 


THE   FLOWER  AND   THE   BEE 

fly  with  wings  as  transparent  as  glass,  except  for  a  spot  of  violet 
and  rose,  looks  like  "the  wandering  petal  of  a  flower."  In  the 
variegated  patterns  of  their  wings,  he  declares,  Nature  writes 
as  upon  a  tablet  the  story  of  the  modification  of  species. 
"Therefore,  the  study  of  butterflies — creatures  selected  as 
types  of  airiness  and  frivolity — instead  of  being  despised,  will 
some  day  be  valued  as  one  of  the  most  important  branches 
of  biological  science." 

Bates's  words  were  prophetic,  and  it  is  to-day  generally 
recognized  that  the  brilliant  markings  on  the  wings  of  butter- 
flies offer  to  students  of  evolution  and  heredity  a  most  promising 
field  for  investigation.  Eimer,  who  based  his  theory  of  ortho- 
genesis chiefly  on  these  patterns  and  colorings,  says:  "Like  the 
leaves  of  an  open  book  the  written  characters  on  the  wings  of 
our  butterflies  show  their  past  and  present  history." 

According  to  the  catalogue  published  by  the  United  States 
National  Museum,  in  1902,  there  are  in  North  America  6,622 
species  of  Lepidoptera,  of  which  652  are  butterflies  and  5,970 
are  moths.  While  in  other  orders  of  insects  a  part  of  the 
species  live  upon  other  substances  than  nectar  and  pollen,  all 
of  the  Lepidoptera  are  adapted  to  a  floral  diet.  But  since  they 
do  not  collect  pollen  but  feed  on  nectar  alone,  they  are  far  less 
important  than  bees  as  pollinators  and  much  less  constant  in 
their  visits.  Doubtless  all  the  butterflies  at  times  visit  flowers, 
but  only  about  107  have  actually  been  collected  on  flowers 
in  North  America  and  111  in  Europe.  Many  adult  moths  do 
not  take  any  food  at  all,  so  that  with  the  exception  of  the  hawk- 
moths  and  a  few  other  families,  notwithstanding  their  great 
numbers,  they  are  not  frequently  observed  sucking  nectar.  In 
North  America,  including  25  species  of  hawk-moths,  or  Sphin- 
gidce,  only  82  have  been  listed  as  flower- visitors;  and  in  Europe 
186,  of  which  36  are  hawk-moths.     The  tubular  proboscis  or 

126 


Fig.  59.     Sweet-William.     Dianthus  barhatus 
A  butterfly-flower 


THE  FLOWER  AND   THE  BEE 

tongue,  which  is  carried  coiled  beneath  the  head,  varies  in 
length  from  ^V  of  an  inch  to  more  than  10  inches;  and  is  formed 
by  the  extension  of  the  blades  of  the  maxillae,  which  are  held  to- 
gether by  minute  hooks  so  that  it  is  practically  air-tight. 

Among  butterfly-flowers  none  are  more  widely  known  than 
the  pinks.  They  exhibit  a  wonderful  variety  of  red  shades, 
varying  from  white,  through  rose,  pink,  and  deep  red  to  scarlet 
and  crimson.  The  petals  may  be  marbled  or  dotted  with 
white,  with  a  white  centre,  surrounded  by  a  purple  ring,  as  in 
Dianthus  deltoides.  The  corolla  is  often  notched  or  fringed 
and  surmounted  by  a  corona  of  scales.  The  perfume  is  aro- 
matic, and  the  nectar  is  deeply  concealed.  The  red-flowered 
pinks  are  adapted  to  pollination  by  butterflies  by  which  they 
are  chiefly  visited. 

The  variegated  flowers  of  the  sweet-william,  or  bunch- 
pink  {Dianthus  harhatus),  familiar  in  every  flower-garden,  dis- 
play the  most  vivid  shades  of  crimson  and  scarlet  and,  as  the 
name  indicates,  exhale  a  pleasant  fragrance.  (Fig.  59.)  They 
are  adapted  to  pollination  by  butterflies  and  day-flying  moths. 
The  nectar  lies  at  the  bottom  of  a  long  calyx-tube  beyond  the 
reach  of  honey-bees,  which  I  have  seen  vainly  thrusting  their 
tongues  down  the  centre  of  the  flowers,  probing  between  the 
petals,  and  even  looking  under  the  corolla. 

The  carmine  flowers  of  the  stemless  catchfly  {Silene  acaulis), 
which  grows  in  the  higher  Alps,  are  very  frequently  visited  by 
butterflies,  upon  which  they  are  dependent  for  pollination. 
Two  species  of  Lychnis  have  beautiful  bright- red  flowers, 
which  are  very  attractive  to  butterflies.  Twenty-eight  dif- 
ferent species  of  butterflies  have  been  taken  on  the  handsome, 
red  flowers  of  the  soapwort  {Saponaria  ocymoides);  the  pinks 
{Dianthus)  also  have  the  nectar  so  deeply  concealed  that  it  can 
be  reached  only  by  Lepidoptera,  a  part  of  the  elegant  red  flowers 

128 


Fig.  60.     Orange-Red  Lily.     Lilium  philadeiphicum 
A  butterfly-flower 


THE   FLOWER  AND   THE   BEE 

being  adapted  to  butterflies,  and  a  part  to  diurnal  hawk-moths. 
*'As  the  honey  gets  more  deeply  concealed  and  access  more 
directly  limited  to  butterflies,  we  find,"  says  Hermann  Mueller, 
"'pari  passu  among  the  Carijophyllaceoe  (pink  family)  increasing 
development  of  sweet  scents,  bright-red  colors,  fine  markings 
round  the  entrance  of  the  flower,  and  indentations  at  the  cir- 
cumference. All  these  characters,  which  are  so  attractive  to 
us,  seem  to  have  been  produced  by  the  similar  tastes  of  butter- 
flies." This  conclusion  is  much  strengthened  by  the  fact  that 
nocturnal  flowers  are  usually  white  and  without  variegation. 

The  wild  orange-red  Hly  {Lilium  philadelphicum) ,  which 
grows  in  dry,  upland  pastures,  is  polhnated  by  butterflies 
(Fig.  60),  while  the  wild  yellow  lily  {Lilium  canadense),  which 
blooms  along  the  marshy  river-banks,  is  polhnated  by  bees. 
The  bee-lily  is  an  inverted,  bell-shaped  flower  with  broad  over- 
lapping floral  leaves,  which  shed  the  rain  perfectly.  Bees 
ahght  on  the  stigma  and  crawl  up  the  style  to  the  nectar  at 
the  bottom  of  the  flower.     (Fig.  61.) 

But  the  butterfly-lily  stands  erect,  and  the  floral  leaves  are 
contracted  at  base  into  narrow  claws,  leaving  wide  interspaces 
through  which  the  rain  easily  escapes.  If  the  perianth  formed 
a  cup,  like  that  of  the  bee-lily,  it  would  fill  with  water;  and,  if 
it  were  inverted,  it  could  not  be  conveniently  visited  by  butter- 
flies. I  never  fail  to  watch  with  pleasure  the  manoeuvres  of 
butterflies  to  obtain  the  nectar  of  this  wild  lily.  The  narrow 
claw  of  each  perianth  segment  has  its  edges  turned  inward  to 
form  a  groove,  which  guides  the  proboscis  of  the  butterfly  to 
the  nectar-gland  at  its  base.  The  only  visitor  I  have  observed 
is  the  common,  yeUowish-red  butterfly  Argijnnis  aphrodite. 
(Fig.  6^2.)  Alighting  on  the  broad  limb  of  the  flower,  it  runs 
its  tongue  down  one  of  the  grooves  to  the  nectar,  while  at  the 
same  time  its  wings  come  in  contact  with  the  anthers  and 

130 


BUTTERFLY-FLOWERS 

stigma.  The  anthers  are  covered  all  around  with  pollen  and 
are  versatile,  that  is,  they  are  attached  by  a  middle  point  and 
when  touched  oscillate  easily  up  and  down  like  the  walking- 
beam  of  an  engine.     In  the  bee-lily  the  anthers  are  fixed  in 


Fig.  G1.     Canada  Lily.     Lilium  canadense 
A  bee-lily 


one  position.     A  third  species  of  lily  (Z.  Martagon)  is  adapted 
to  hawk-moths. 

Lepidopterid,  or  butterfly  and  moth  flowers,  are  not  numer- 
ous, and  in  the  whole  Alpine  flora  Mueller  found  but  33. 
Besides  the  pinks  and  lilies  already  mentioned,  several  red- 
flowered  species  of  Phlox    (Fig.  63),   a  crimson  heath   {Erica 

131 


THE  FLOWER  AND  THE  BEE 

carnea),  and  5  or  6  red-flowered  primroses  are  pollinated  by 
butterflies.  Many  lepidopterid  flowers  occur  among  the 
orchids,  and  in  the  genus  Habenaria  the  beautiful,  purple- 
fringed  orchis  is  a  butterfly-flower  (Fig.  64),  while  the  greenish 
or  white  species  are  pollinated  by  crepuscular  or  nocturnal 
moths.  In  some  instances  I  have  found  the  grayish  hairs  of 
moths  adhering  to  glutinous  surfaces. 

Butterflies  do  not  confine  their  visits  to  butterfly-flowers 
alone,  but  may  visit  any  flower.  They  experience,  however, 
more  or  less  difficulty  in  sucking  nectar  on  flat  surfaces  and 
consequently  prefer  tubular  flowers  with  concealed  nectar — 
the  longer  the  tongue  the  more  marked  this  preference  becomes. 
They  also  occasionally  fly  to  pollen-flowers  and  search  them  for 
sweet  secretions.  But  no  flowers  are  so  frequently  visited  by 
butterflies  as  social  flowers  of  the  type  of  the  Compositce,  to 
which  40  to  60  per  cent  of  their  visits  are  made,  or  3  to  6  times 
as  many  visits  as  are  made  to  butterfly  or  bee  flowers.  Every 
one  has  observed  a  cloud  of  butterflies  hovering  over  a  clump 
of  purple  thistle-heads,  or  the  yellow  flowers  of  the  elecampane 
{Inula  Helenium),  or  the  dull-white  clusters  of  the  thorough- 
wort.  The  male  butterflies,  which  are  often  pleasantly  scented, 
pursue  the  females  from  flower  to  flower  without  any  regular 
order. 

Butterflies  often  rob  flowers  of  their  nectar  without  render- 
ing any  service  in  return.  Both  honey-bees  and  butterflies 
steal  thousands  of  pounds  of  alfalfa  nectar  annually  through  a 
crevice  in  the  side  of  the  flower.  Many  other  leguminous 
flowers  are  robbed  in  the  same  way,  but  in  many  species  the 
petals  close  up  so  firmly  that  access  to  the  nectar  can  be  gained 
only  in  the  normal  way.  While  butterflies  cannot  pollinate 
the  flowers  of  the  blue  flag  {Iris  versicolor),  they  often  stand 
on  the  upper  or  under  side  and,  inserting  their  tongues  side- 

132 


\ 

^{^ 

^^^^cr^'^- 

S:'}^' 

\ 

l«^ 

^^lfti^^^4| -'^^ ,  t^^^hm 

'h^ 

Fig.  62.     Orange-Red  Butterfly.     Argynnis  aphrodite 
The  butterfly  which  pollinates  the  orange-red  lily 


THE  FLOWER  AND  THE  BEE 

ways  between  the  sepals  and  petaloid  styles,  suck  the  nectar. 
Indeed,  it  may  easily  happen  in  the  case  of  some  irregular 
flowers,  as  the  larkspur,  that  butterflies  may  visit  them  nor- 
mally and  obtain  the  nectar,  and  yet  not  touch  either  the 
anthers  or  stigmas  with  their  slender  tongue. 

Butterfly-flowers,  as  has  been  previously  pointed  out,  are 
commonly  red-colored.  Among  the  Alpine  butterfly-flowers 
which  have  red  corollas  are  Orchis  glohosa,  Liliujn  bulbiferum, 
the  heath  Erica  carnea;  the  pinks,  Dianthus  superbus,  D.  sylves- 
tris,  D.  atroruber;  Daphne  striata,  and  Primula  acaule,  and  several 
other  primroses.  Other  red  butterfly-flowers  are  species  of 
Silene,  Lychnis,  Asclepias,  and  Monarda.  "It  is  certainly  not 
purely  accidental,"  says  Mueller,  "that  most  of  the  butterflies 
of  the  Alps,  the  commonest  floral  guests  in  that  region,  are 
vivid-red  in  color,  and  that  bright-red  flowers  are  visited  with 
marked  preference  by  such  butterflies."  Mueller  further  ob- 
served that  orange-hued  composite  flowers,  such  as  hawk's- 
beard  (Crepis  aurea)  and  orange  hawkweed  {Hieracium  auran- 
tiacurri)  are  a  veritable  playground  in  sunny  weather  for 
butterflies  of  fiery-red  color.  Two  copper -colored  butterflies 
were  also  observed  to  fly  to  the  bright-red  fruits  of  the  sorrel. 
This  remarkable  correlation  certainly  deserves  careful  consider- 
ation by  students  of  the  color-sense  of  insects. 

There  would  seem  to  be  no  a  priori  reason  why  red  butter- 
flies may  not  be  strongly  influenced  by  red  flowers.  The  orna- 
mental coloring  of  their  wings  is  largely  the  result  of  sexual 
selection;  and,  since  the  different  sexes  readily  recognize  each 
other,  it  is  not  improbable  that  in  seeking  nectar  they  are 
specially  attracted  by  flowers  of  the  same  color  as  themselves. 
This  view  is  strengthened  by  the  fact  that  blue  butterflies  may 
show  a  preference  for  blue  flowers,  e.  g.,  blue  species  of  Lycoena, 
have  been  seen  to  favor  the  blue  blossoms  of  Phyteuma. 

134 


^ 

"%^ 

w 

1/ 

1^ 

m 

.    1^ 

w 

i 

mWi 

s 

»■■  A^ 

^JJ^H^^^^^^^^^I 

9^ 

J^l 

^^    1 

Fig.  63.     Red  Phlox.     Phlox  paniculata 

A  butterfly-flower 


THE  FLOWER  AND   THE   BEE 

Red  waves  of  light,  as  is  well  known,  excite  attention  and 
are  seen  where  other  hues  are  passed  by  unnoticed;  they  are 
the  longest  waves  of  the  solar  spectrum  and,  like  long  oceanic 
waves,  possess  a  great  amount  of  energy.  Are  not  red  flags 
constantly  used  for  signals,  and  do  not  soldiers  to-day  avoid 
wearing  scarlet  uniforms?  In  moderation  red  is  a  warm,  stim- 
ulating color,  and  is  frequently  used  in  wearing  apparel,  in  pic- 
tures, and  in  the  decoration  of  walls  and  ornaments;  but  in 
excess  it  produces  irritation  and  anger.  It  enrages  the  turkey 
gobbler  of  the  farmyard  and  excites  the  Texas  steer  to  madness. 
Physicians  tell  us  that  people  living  continually  in  bright-red 
rooms  are  apt  to  be  irritable  and  quarrelsome,  but  that  when 
the  walls  are  painted  a  quieter  hue,  as  pale  blue  or  drab,  these 
nervous  symptoms  speedily  disappear. 

Edible  berries  are  more  often  red  than  any  other  color. 
Bird-flowers  are  almost  invariably  fire-red  or  scarlet.  In  trop- 
ical America,  where  there  are  more  than  five  hundred  species 
of  humming-birds,  there  are  scores  of  scarlet  bird-flowers,  as 
scarlet  sages,  fuchsias,  and  abutilons;  while  in  Europe,  as 
Kemer  has  pointed  out,  where  neither  the  humming-birds  of 
America  nor  the  sun-birds  of  Africa  nor  the  honeysuckers  of 
Australia  are  found,  scarlet  blossoms  are  noticeably  absent. 
It  is  difficult  not  to  believe  that  anthophilous  birds  have  learned 
to  associate  bright-red  colors  with  the  presence  of  an  ample 
food-supply  of  nectar  and  small  insects. 

It  is,  on  the  other  hand,  noteworthy  that  in  the  families  and 
genera  which  contain  red  butterfly-flowers  blue  is  very  rare 
or  wholly  absent.  There  are  no  blue  flowers  in  the  pink  family, 
and  in  the  orchis  family  out  of  6,000  species  there  is  only  1 
blue  form,  Vanda  coerulea,  from  India.  Neither  are  all  butter- 
fly-flowers red,  for  in  the  genus  Glohularia  there  are  3  bright- 
blue  species  which  are  adapted  to  butterflies,   "the  only  in- 

136 


Fig.  64f.     Purple-Fringed  Orchis,     llahenaria  psychodes 
A  butterfly-flower 


THE  FLOWER  AND  THE  BEE 

stance  in  the  German  and  Swiss  flora  of  a  blue  color  being 
produced  by  the  selective  agency  of  the  Lepidoptera.''  Butter- 
flies, moreover,  do  not  confine  themselves  chiefly  to  red  flowers, 
but  visit  a  great  variety  of  colors,  and  of  1,43*2  visits  made  by 
100  species,  45  per  cent  were  made  to  yellow  and  white  flowers, 
and  55  per  cent  to  red  and  blue  flowers.  The  dingy-white 
flowers  of  the  thoroughwort  are  often  alive  with  butterflies. 
Finally  butterflies  visit  the  level-topped  inflorescence  of  the 
CompositoB,  which  offers  good  landing-places  and  abundant 
nectar  in  slender  tubes,  more  frequently  than  any  other  flowers, 
which  would  show  that  they  were  influenced  by  form  more  than 
by  color.  It  seems,  therefore,  an  open  question  whether  the 
red  coloration  of  butterfly-flowers  is  not  largely  an  incidental 
result,  rather  than  due  to  the  selective  agency  of  butterflies. 


138 


CHAPTER  IX 
NOCTURNAL  OR  HAWK-MOTH   FLOWERS 

FLOWERS  which  bloom  in  darkness  seem  weird  and  un- 
natural. Most  conspicuous  blossoms  are  creatures  of 
sunshine  and  warmth,  and  seek  to  allure  diurnal  insects, 
while  many  of  them  close  at  the  approach  of  night.  But  noc- 
turnal flowers  are  adapted  to  pollination  by  moths,  chiefly 
hawk-moths.  How  this  reciprocal  relation  became  established 
it  would  be  hard  to  tell;  but  their  forms,  time  of  opening,  and 
colors  easily  distinguish  them  from  the  day-bloomers. 

Consider,  for  instance,  the  thorn-apples  {Datura),  which  have 
long,  slender  corolla  tubes  some  six  inches  in  length.  (Fig.  Q5.) 
They  are  "children  of  the  dewy  moonlight,"  and  fill  the  eve- 
ning air  with  their  sweet  fragrance.  Their  large,  pale,  salver- 
shaped  blossoms  "serenely  drooping  awaken  visions  of  silent 
awe,"  and  it  is  at  once  apparent  that  these  stately  flowers  do 
not  invite  the  visits  of  bees.  Some  fifty  years  ago  Felicia 
Hemans  was  a  popular  poet  in  New  England,  and  while  she 
probably  knew  nothing  of  the  mysteries  of  flower-pollination, 
in  her  lines  to  Datura  arborea  she  instinctively  recognizes  the 
fact  that  bees  are  not  found  in  this  domain  of  shadows: 

"Majestic  plant!    such  dreams  as  lie 
Nursed,  where  the  bee  sucks  in  tlie  cowslip's  bell. 
Are  not  thy  train: — those  flowers  of  vase-like  swell, 
.  .  .  worthy,  carved  by  plastic  hand, 
Above  some  kingly  poet's  tomb  to  sliine 
In  spotless  marble." 

139 


THE  FLOWER  AND  THE  BEE 

In  their  relations  to  flowers  moths  may  be  divided  into  two 
groups,  the  highly  specialized  hawk-moths  {Sjphingidce)  and  the 
other  moth  families.  Many  moths  fly  only  on  the  rainiest 
and  darkest  nights.  We  should  like  to  know  more  of  the  devious 
ways  of  these  nocturnal  wanderers  amid  the  down-pouring  rain. 
They  seem  a  bit  uncanny.  Among  the  smaller  moths  most 
frequently  observed  on  flowers  are  the  measuring-moths 
(GeometridcB) ,  the  leaf -rollers  {TortricidGe),  the  owlet  moths  or 
noctuids  (Noduidce),  and  the  teneids  or  the  little  moths  of  the 
family  Teneidce,  the  larvae  of  which  mine  in  leaves.  Few  of 
them  are  common  floral  visitors,  or  of  much  significance  in 
pollination.  Several  of  the  hawk -moths,  as  the  clear-winged 
moths,  fly  regularly  in  the  daytime. 

The  yuccas,  or  Spanish  bayonets,  liliaceous  plants  which  are 
widely  distributed  in  this  country  and  Mexico,  are  entirely 
dependent  for  pollination  on  little  teneid  moths  of  the  genus 
Pronuba.  If  the  phenomena  attending  the  transfer  of  the 
pollen  had  not  been  investigated  by  Riley  and  Trelease  in 
every  detail  they  would  seem  as  incredible  as  a  tale  of  Munch- 
ausen. The  large,  pendulous  flowers  are  creamy-white  tinged 
with  green  or  rose,  and  are  borne  in  magnificent  clusters 
or  panicles,  which  are  well  worthy  of  the  admiration  they  ex- 
cite. Subtropical  species  of  this  genus  become  arboreal  and 
reach  an  altitude  of  30  feet.  In  California  Yucca  Whipplei 
sends  up  a  flower-stalk  12  feet  high,  which  for  nearly  half  its 
length  bears  an  imposing  cluster  of  flowers.     (Fig.  66.) 

Since  the  large,  bell-shaped  flowers  hang  downward  and  the 
stigmas  stand  in  advance  of  the  anthers,  self-pollination  is  im- 
possible, for  the  pollen  is  too  glutinous  to  be  carried  by  the 
wind,  and  if  accidentally  dislodged,  it  falls  directly  to  the 
ground.  The  continued  existence  of  the  yuccas,  therefore, 
depends  chiefly  on  the  little  moths  of  Pronuba.     The  female 

140 


Fig.  65.     Thorn-Apple.     Datura  Tatula 
A  hawk-moth  flower 


£i>-^--l 


Fig.  66.     Yucca  Whipplei  of  California 
Twelve  feet  tall.     The  magnificent  cluster  of  flowers  is  about  six  feet  long.     (After  Rilev) 


NOCTURNAL   OR   HAWK-MOTH    FLOWERS 

Pronuba  is  unique  among  all  the  thousands  of  moths  and  butter- 
flies in  the  world  in  that  she  has  maxillary  tentacles  for  col- 
lecting pollen,  and  a  horny  ovipositor  for  piercing  succulent 
tissue.  In  the  collection  of  pollen  she  resembles  the  bees,  and 
in  the  manner  of  laying  her  eggs  the  ichneumon-flies — both 
hymenopterous  insects. 

The  most  widely  cultivated  and  best-known  species  of 
yucca  is  Adam's  needle,  or  Spanish  bayonet  (Y.  filamentom), 
which  is  pollinated  by  Pronuba  yuccasella.  Soon  after  twilight 
falls  these  little  white  moths  fly  from  flower  to  flower  gathering 
from  the  anthers  with  their  trunk-like  tentacles,  which  are 
covered  with  short  spines,  the  sticky  masses  of  pollen,  until  a 
ball,  sometimes  twice  or  three  times  as  large  as  her  head,  has 
been  accumulated.  Then  she  usually  flies  away  to  another 
plant,  and  alighting  on  the  seed-pod  pierces  the  wall  with  her 
saw-like  ovipositor  and  deposits  an  egg  in  one  of  the  rows  of 
ovules.  After  3  or  4  eggs  have  thus  been  laid  the  moth  as- 
cends to  the  top  of  the  pistil,  and  in  the  funnel  formed  by 
the  stigmas,  which  are  receptive  only  on  the  inner  surface, 
she  crowds  the  ball  of  pollen.  Apparently  she  intentionally 
pollinates  the  flowers,  for  if  she  failed  to  perform  this  service 
no  seed  would  be  produced  and  her  offspring  would  })erish  for 
want  of  food.  The  moth  herself  receives  no  direct  benefit  since 
her  tongue  has  lost  its  sucking  function  and  she  no  longer  takes 
food.     (Fig.  67.) 

The  possession  of  an  ovipositor  and  spined  tentacles  by  a 
genus  of  moths,  and  the  collection  and  placing  of  pollen  on  the 
stigmas  are  structures  and  functions  which  stand  alone  in  the 
history  of  flower-pollination.  While  it  seems  incredible  that 
Pronuba  can  understand  that  unless  pollen  is  placed  on  the 
stigmas  no  seed  will  be  produced,  the  more  her  behavior  is 
investigated  the  stronger  becomes  the  evidence  that  such  is  the 

143 


THE   FLOWER  AND   THE   BEE 

fact.  Riley  at  first  believed  that  the  stigmatic  fluid  was  a  form 
of  nectar,  which  attracted  the  moth  to  the  stigmas.  The  ball 
of  pollen,  he  thought,  might  have  been  accunmlated  acci- 
dentally and,  proving  an  encumbrance  while  the  insect  was 
feeding,  was  dislodged  and  left  in  the  stigmatic  cavity.  But 
twenty  years  of  experience  and  the  discovery  that  Pronuha 
passed  her  life  without  taking  food  compelled  him  to  admit 
that  her  acts  were  "more  unselfish." 

Kerner  looks  upon  this  act  as  "unconsciously  purposeful,'* 
and  compares  it  with  the  instinct  of  those  caterpillars  which, 
living  in  the  hard  parts  of  wood,  before  they  pass  into  the 
chrysalid  stage  make  a  special  exit  by  which  the  tender  adult 
insects  may  emerge  into  the  world.  But  it  is  not  difficult  to 
see  how  this  latter  habit  has  arisen.  These  larvae  undoubtedly 
at  first  underwent  their  transformations  outside  of  the  plant, 
but  later  remained  within  their  burrows  for  the  sake  of  the 
greater  protection  afforded.  Instinctively  they  continued  to 
make  an  exit.  The  habit  has  never  weakened,  since  any  cater- 
pillar which  failed  to  make  an  opening  left  no  descendants. 

Coquillet  would  regard  the  behavior  of  Pronuba  as  a  purely 
intelligent  act.  "There  appears  to  be  no  doubt,"  he  says, 
"that  she  was  in  possession  of  the  fact  that,  unless  she  did  thus 
pollinate  the  flower,  there  would  be  no  seed-pods  for  her  off- 
spring to  live  on."  But  it  seems  past  belief  that  Pronuba  has 
long  been  in  possession  of  knowledge  that  has  only  recently 
become  known  to  the  human  race.  It  is  far  more  probable  to 
suppose  that  the  pollen  was  collected  at  first  for  some  purpose 
useful  to  the  species,  although  it  is  difficult  to  imagine  in  what 
way,  for  there  is  no  reason  to  believe  that  the  larvae  were  ever 
fed  with  pollen,  as  in  the  case  of  the  brood  of  bees.  It  w^ill  be 
noticed  that  the  moth  gathers  the  ball  of  pollen  before  she 
lays  her  eggs,  and  that,  after  they  have  been  deposited,   she 

144 


Fig.  67.     Twig  from  Flower-Cluster  of  Yucca  Whipplei 

{ud;  2,  flower  open;  3  flower  open  previous  night,  but  now  closed;  4,  the  little  white  moth 
Fromibamwcasella  flying  to  the  flower;  .5,  the  moth  pushing  down  bail  of  pollen  into  the 
funnel  of  stigma;  6,  stigma  enlarged.     (After  Kerner) 


THE  FLOWER  AND   THE  BEE 

stuffs  it  into  the  infundibuliform  stigma.  May  this  not  be  done 
for  the  purpose  of  protecting  her  eggs  by  closing  what  appears 
to  her  hke  an  opening  into  the  seed-capsule?  Bees  and  wasps 
regularly  close  the  entrances  to  their  burrows  for  the  purpose 
of  protecting  their  eggs,  and  it  seems  possible  that  the  moth 
began  filling  the  hollow  stigma  with  pollen  for  the  same  reason. 
Assuming  that  this  was  the  fact,  then  the  flowers  thus  pollinated 
would  be  benefited  from  the  beginning  and  would  produce 
more  seed  than  flowers  depending  for  pollination  on  some  other 
agency.  The  larvae  in  the  seed-capsules  would  be  assured  an 
abundance  of  food,  and  the  moths  would  leave  a  larger  progeny 
than  those  not  possessing  this  habit.  Once  this  practice  was 
established,  it  in  time  became  a  necessity.  Flowers  in  the 
absence  of  the  moths  set  no  seed,  a.nd  moths  failing  to  perform 
this  service  left  no  offspring.  Thus  the  race  of  moths  pollinat- 
ing the  flowers  alone  survived. 

Many  Mexican  cacti  have  large,  strongly  scented,  nocturnal 
white  flowers,  which  are  pollinated  by  hawk-moths.  Among 
these  the  night-blooming  Cereus,  or  "Queen  of  the  Night," 
is  a  not  uncommon  house-plant  in  the  Northern  States,  the 
blooming  of  which  is  often  chronicled  in  country  newspapers. 

Among  butterflies  and  moths  the  hawk-moths  are  easily  the 
most  important  as  flower-pollinators,  and  among  anthophilous 
insects  are  surpassed  only  by  the  bees.  There  are  about  100 
species  in  this  country.  They  are  distinguished  by  their  swift, 
impetuous  flight,  their  large  size,  their  sombre  but  handsome 
garb  of  tan,  brown,  and  gray,  sometimes  marked  with  yellow 
or  red,  and  their  elegant  forms.  They  exhibit  a  high  degree 
of  flower  fidelity  and  make  their  visits  with  astonishing  rapidity, 
a  species  of  Macroglossa  having  been  observed  in  the  Alps  to 
visit  several  hundred  flowers  of  a  primrose  in  a  few  minutes. 
Since  the  nocturnal  species  do  not  fly  in  stormy  weather,  but 

U6 


THE   FLOWER  AND   THE   BEE 

mostly  on  calm,  warm  evenings  and  are  far  from  abundant, 
their  swift  flight  is  a  great  advantage  in  enabling  them  to  polli- 
nate many  flowers  in  a  short  time.  Hawk-moths  have  the 
sense  of  smell  very  strongly  developed,  and  consequently  noc- 
turnal flowers  are  usually  odoriferous.     (Fig.  68.) 

Two  genera  of  hawk -moths  fly  in  the  daytime,  the  clear- 
winged  moths  Hemaris  and  Macroglossa.  Some  species  of 
Macroglossa  so  closely  resemble  humming-birds  in  their  appear- 
ance and  manner  of  flight  that  the  natives  of  South  America, 
according  to  Bates,  believe  that  one  can  be  transmuted  into 
the  other.  Bates  himself,  several  times  by  mistake,  shot  a 
hawk-moth  instead  of  a  humming-bird,  and  it  was  long  before 
he  could  distinguish  the  one  from  the  other  on  the  wing.  The 
little  children  of  Fritz  Mueller  came  running  to  him  one  day 
and  declared  in  great  excitement  that  they  had  seen  a  six- 
legged  humming-bird. 

A  common  cultivated  hawk -moth  flower  is  the  sweet- 
scented,  climbing  honeysuckle  {Lonicera  Peridymeniun,  Fig. 
69.)  The  flowers  expand  early  in  the  evening  and  are  at  first 
white  within  and  purplish  without.  The  pistil  is  bent  abruptly 
downward,  while  the  anthers  stand  directly  in  front  of  the 
entrance,  by  which  arrangement  self-pollination  is  prevented. 
The  fragrance  is  very  powerful  and  may  be  perceived  at  a  long 
distance.  In  the  daytime  Kerner  placed  a  hawk-moth  300 
yards  away  and  marked  it  with  cinnabar.  When  twilight  fell, 
the  moth  began  to  move  the  feelers,  which  serve  it  as  olfactory 
organs,  hither  and  thither  a  few  times,  then  stretched  its  wings 
and  flew  like  an  arrow  through  the  garden  to  the  honeysuckle. 
In  the  dusk  I  have  often  seen  several  species  of  moths  darting 
swiftly  from  flower  to  flower  and,  as  they  poised  for  a  few 
seconds  in  the  air,  coming  in  contact  with  the  anthers  and 
covering  the  whole  under-side  of  the  body  with  pollen.     x\s  a 

148 


Fig.  69.     Climbing  Honeysuckle.     Lonicera  Peridyi 
A  hawk-moth  flower 


THE   FLOWER  AND   THE   BEE 

landing-stage  would  be  in  the  way,  the  lobes  of  the  petals  are 
turned  backward.  By  the  second  evening  the  corolla  has 
changed  within  from  white  to  yellow,  the  stamens  have  bent 
downward,  while  the  stigma  has  moved  upward  and  now 
stands  in  front  of  the  entrance.  The  flowers  are  also  occa- 
sionally visited  by  bumblebees,  which  are  able  to  reach  a  part 
of  the  nectar.  Very  Hkely  the  honeysuckle  was  once  a  bumble- 
bee flower,  but  the  corolla -tube  has  lengthened  to  such  an  ex- 
tent in  response  to  the  visits  of  moths  that  the  bumblebees  are 
at  present  nearly  excluded.  The  flowers  are  frequently  visited 
by  humming-birds  in  the  daytime. 

The  yellow  evening-primrose  {(Enothera  biennis),  so  common 
in  hedgerows  and  waste  land,  is  also  pollinated  by  hawk-moths, 
but  in  this  locality  they  are  not  frequent  visitors.  The  flowers 
expand  so  quickly  at  about  dusk  that  the  motion  of  the  petals 
is  clearly  visible.  The  anthers  are  open  and  are  covered  with 
pollen,  but  the  four  lobes  of  the  stigma  are  folded  close  together. 
The  day  following  the  anthers  shrivel  and  the  four  stigmatic 
lobes  diverge,  forming  a  cross,  which  a  hawk -moth  cannot  fail 
to  touch.  However  it  may  have  been  in  the  past,  the  flowc^-s 
at  the  present  time  do  not  appear  to  attract  a  sufficient  number 
of  visitors,  for  according  to  the  observations  of  De  Vries  in 
Europe  and  of  Davis  in  xVmerica  they  are  regularly  pollinated 
in  the  bud.     (Fig.  70.) 

Close  by  the  evening-primrose  I  often  find  the  night-flowering 
catchfly  {Silene  iioctiflora),  called  catchfly  because  the  whole 
plant  is  viscid,  hairy,  and  destructive  to  many  small  flies.  The 
small  white  flowers  open  at  sundown,  but  I  have  found  them 
very  sparingly  visited  by  moths.     (Figs.  71,  72,  and  73.) 

Of  the  other  moth-flowers  only  a  few  of  the  more  common 
can  be  mentioned  here;  they  are  characterized  by  having  white 
or  nearly  white  flowers  which  open  in  the  evening,  have  long 

150 


NOCTURNAL   OR   HAWK-MOTH   FLOWERS 

corolla-tubes,  and  are  sweet-scented.     In  the  pink  family  there 
are  the  sand-pink  {Dianthiis  arenaria),  bouncing  bet  {Saponaria 


Fig.  70.     Evening-Primrose.     CEnothera  biennis 

A  hawk-moth  flower 

officinalis)  common  along  roadsides  (Fig.  74),  white  lychnis 
(L.  album),  and  evening-lychnis  {L.  vespertina),  and  the 
long-flowered    catchfly    {Silene    longiflora),   and    the    nodding 

151 


Fig.  71.     Night-Flowering  Catchfly.     Silene  noctiflc 


Fig.  72.     White  Catchfly.     Silene  Armeria 


THE   FLOWER  AND  THE  BEE 


catchfly  (>S.  nutans).     Exotic  moth-flowers  are  also  common  in 
the  nightshade  family,  as  several  cultivated  species  of  tobacco, 

the  long-flowered  to- 
bacco {Nicotiana  longi- 
^ora),  which  has  a  green 
tube  4  inches  long,  and 
the  similarly  flowered 
night-blooming  tobacco 
(A^  nodiflora,  Fig.  74a), 
and  the  white  flowers 
of  the  Jamestown  weed, 
which  are  3  inches  long. 
Two  species  of  lilies  are 
pollinated  by  hawk- 
moths,  as  Lilium  candi- 
dum  and  L.  Martagon, 
as  are  also  several  spe- 
cies of  gentians  {Gen- 
tiana  verna  and  G. 
bavarica),  the  vernal 
crocus  {Crocus  vernus), 
several  kinds  of  the 
sweet-scented  Gardenia 
and  a  number  of  or- 
chids in  the  genus  Ha- 
benaria.     (Fig.  75.) 

Several  years  ago  at 
C  amb ridge,    Mass.,    I 
saw  in  bloom  that  re- 
markable  orchid   from 
Madagascar,  AngrwcuTn  sesquipedale,  which  bears  large,  snow- 
white  flowers  with  a  slender  green  nectary  of  the  astonishing 

154 


Fig.  73.     Racemed  Catchfly.     Silene 
dichotoma 


Fig.  74.     Bouncing  Bet.     Sapoiiaria  officinalis 
A  hawk-moth  flower 


Fig.  74a.     Night-Blooming  Tobacco.     Nicotiana  nodiflc 
A  hawk-moth  flower 


Fig.  75.     White  Variety  of  Purple-Fringed  Orchis.     Ilabenaria  psychodes 


THE  FLOWER  AND   THE  BEE 

length  of  11  inches.  It  seemed  impossible  at  the  time  of 
the  discovery  of  this  plant  that  there  should  be  in  existence 
a  moth  with  a  tongue  long  enough  to  consume  all  of  the 
nectar,  but  such  a  moth  was  later  actually  found.  To  re- 
move the  pollen  masses  it  must  thrust  its  long  proboscis 
into  the  nectary  up  to  its  very  base.  If  these  great  moths 
were  to  become  extinct,  then  assuredly  Angroecum  would  also 
become  extinct,  for  smaller  moths  are  unable  to  remove  the 
polHnia.  On  the  other  hand,  as  Darwin  states,  there  will 
always  be  an  inch  or  more  of  nectar  at  the  base  of  these  long 
nectaries  safe  from  the  depredations  of  other  insects,  upon  which 
the  moths  are  probably  largely  dependent.  Thus  the  destruc- 
tion of  either  the  plant  or  the  moth  would  be  fatal  to  the  sur- 
vivor. The  tongues  of  the  moths  tend  continually  to  increase 
in  length  in  order  that  they  may  drain  the  last  drop  of  nectar, 
while  the  nectaries  which  are  long  enough  to  compel  the  moths 
to  insert  their  tongues  up  to  the  very  base  will  be  the  best 
fertilized.  Thus  there  is  a  race  between  the  moths  and  the 
plants,  in  which  Angrcecum  has  triumphed,  for  it  still  flourishes 
abundantly  in  the  forests  of  Madagascar. 

There  was  undoubtedly  a  time  in  the  history  of  butterfly 
and  moth  flowers  when  the  nectar  was  less  deeply  concealed 
than  at  present  and  was  accessible  to  bees.  Concealment  of 
the  nectar  was  at  first  beneficial  by  shutting  out  marauding 
beetles  and  flies.  And  at  this  point  the  lengthening  of  the 
nectaries,  or  corolla-tubes,  should  have  stopped,  for  bees  are 
the  most  valuable  of  pollinators,  and  as  a  general  principle 
it  is  a  disadvantage  for  a  flower  to  be  dependent  on  a  single 
species  or  genus  of  insects  for  pollination.  But  variation  in 
the  direction  of  increased  length  of  the  nectaries  once  started, 
the  impulse  still  continued,  and  the  tongues  of  the  visiting 
moths  and  butterflies  lengthened  correspondingly.      The  ne- 

158 


NOCTURNAL    OR    HAWK-INIOTH    FLOWERS 

cessity  of  building  nests  and  caring  for  their  young  made  this 
impossible  in  the  case  of  bees.  Just  as  the  momentum  of  a 
swinging  pendulum  carries  it  beyond  the  central  point  of  equi- 
librium, so  the  momentum  of  the  variation  carried  the  length 
of  the  nectaries  to  a  point  where  bees  were  excluded.  Thus 
butterfly  and  moth  flowers  came  into  existence;  but  this  re- 
ciprocal dependence  does  not  in  most  cases  imply  more  effec- 
tive pollination,  although  the  Lepidoptera  are  assured  a  larger 
supply  of  nectar.  Tendency  to  vary  in  a  definite  direction, 
even  when  no  benefit  is  derived,  is  shown  by  the  increasing 
complexity  of  the  markings  on  the  wings  of  insects  and  the 
convolutions  on  the  margins  of  shells.  It  is  not  at  all  improb- 
able that  the  nectaries  of  certain  flowers  and  the  tongues  of 
the  visiting  Lepidoptera  may  continue  to  lengthen  until  both 
become  extinct. 

An  intricate  mechanism  to  effect  polHnation  does  not  prove 
that  such  an  arrangement  is  best  for  flowers  in  general.  It 
finds  its  explanation  in  the  particular  conditions  under  which 
each  flower  was  developed.  Nature  seems  at  times  to  be  a 
very  poor  teleologist.  The  wonderful  orchids  are  less  success- 
ful than  many  lowly  dooryard  weeds.  In  the  case  of  certain 
flowers  orthogenesis,  or  determinate  variation  in  a  definite 
direction,  has  carried  forward  their  specialization  until  they 
are  face  to  face  with  extinction. 


159 


CHAPTER   X 
FLY-FLOWERS 

THAT  the  physical  characters  of  flower-visiting  insects, 
such  as  size  and  the  length  of  the  tongue,  should  influ- 
ence the  structure  of  flowers  would  be  expected;  but  it 
is  more  surprising  to  find  their  mental  traits  also  reflected. 
How  different  is  the  reception  accorded  by  flowers  to  many 
stupid  flies  from  that  given  to  bees  !  Notice  how  the  con- 
stant and  observant  bees  are  offered  nectar,  pollen,  shelter,  an 
alighting-platform,  bright  hues,  and  sweet  odors,  while  unde- 
sirable guests  are  excluded.  But  for  the  unspecialized,  stupid 
flies  there  are  pitfall-flowers,  prison-flowers,  pinch-trap  flowers, 
and  flowers  with  deceptive  nectaries,  deceptive  colors  and 
odors.  In  her  readiness  to  take  advantage  of  their  weakness 
Nature  simulates  the  worse  qualities  of  humanity,  although, 
more  strictly  speaking,  it  is  their  inability  to  learn  from  observa- 
tion that  has  induced  the  development  of  these  peculiar  forms. 
But  not  all  flies  are  stupid.  This  is  far  from  true  of  the  syrphid 
or  hover  flies  and  the  bee-flies  which  visit  nearly  the  same 
flowers  as  do  the  bees. 

Their  numbers  and  activity  probably  entitle  the  flies  to  rank 
after  the  bees  and  before  the  butterflies  and  moths  as  flower- 
pollinators.  Mueller  places  them  next  to  the  Hymenoptera, 
except  in  the  case  of  the  Alpine  flora,  where  butterflies  are  very 
abundant.  In  New  Zealand  both  bees  and  butterflies  are  very 
scarce,  and  Thomson  considers  the  flies  as  the  chief  agents  in 
pollination. 

There  are  in  North  America  more  than  8,000  described  species 
of  two-winged  flies,  or  Diptera.    Very  many  of  them  live  largely 

160 


FLY-FLOWERS 

or  wholly  on  animal  substaiices,  and  never,  or  only  rarely, 
visit  flowers.  To  this  group  belong  mosquito-like  flies  with 
long  antennae,  small  heads  and  eyes,  slender  bodies,  and  long 
legs,  as  the  crane-flies,  midges,  mosquitoes,  i)unkies,  gall- 
gnats,  March-flies,  and  black-flies.  Flies  which  visit  flowers 
frequently  for  nectar  and  poUen  resemble  the  house-fly,  and 
usually  have  short  antennae,  large  heads  and  eyes,  robust  bodies, 
and  short  legs,  as  the  horse-flies,  soldier-flies,  ro})l)er-flies,  bee- 
flies,  house-flies,  dance-flies,  syrphid  flies,  and  flesh-flies. 

The  habit  of  visiting  flowers  has  been  acquired  independently 
in  many  different  families  of  flies,  and  all  the  intermediate 
stages  may  be  found  between  forms  which  are  jiredaceous  and 
those  which  hve  wholly  on  floral  food.  Mosquitoes,  especially 
the  males,  occasionally  visit  flowers,  and  one  genus  {Megar- 
rkinus)  never  sucks  blood,  but  in  both  hemispheres  has  been 
observed  to  feed  on  nectar  alone.  The  males  of  the  horse-flies, 
or  blood-thirsty  Tehanidoe,  live  on  nectar,  while  the  females 
usually  suck  the  blood  of  animals,  but  occasionafly  visit  flowers. 
The  syrphid  flies  in  the  adult  stage  depend  chiefly  on  pollen 
and  nectar,  while  the  bee-flies  feed  only  on  nectar. 

Flowers  with  nauseous  or  indoloid  odors,  due  to  the  decom- 
position of  some  nitrogenous  compound,  are  attractive  to  flesh 
or  carrion  flies.  The  petals  are  often  flesh-colored,  blood-red, 
dull  dark-purple,  marked  with  lurid  stripes  or  spots.  To 
some  observers  they  suggest  putrefying  flesh  or  decaying  car- 
casses, but  in  most  instances  the  resemblance  is  not  very  appar- 
ent. There  are  also  malodorous  flowers  which  are  yellowish 
green  or  white.  It  is  chiefly  the  nauseous  odor  rather  than  a 
likeness  to  putrid  substances  which  draws  to  flowers  carrion 
and  dung  flies  belonging  to  the  genera  Musca,  Lucilia,  Calli- 
phora,  and  Sarcophaga.  Many  strong-scented  odors,  which  are 
not  repulsive,  are  also  attractive  to  flies. 

161 


THE   FLOWER  AND   THE   BEE 

In  damp  thickets  on  the  banks  of  rivers,  twining  amid  the 
bushes  there  grows  a  pretty  vine  with  smilax-hke  leaves  and 
umbels  of  green  flowers  pollinated  by  flies.     (Fig.  76.)     This 


Fig.  76.     Carrion-Flower.     Smilax  herbacea 
A  fly-flower 


is  the  carrion-flower  and  so  offensive  is  its  odor  that  it  well 
merits  the  name.  Another  carrion-flower  is  the  purple  trillium 
{Trillium  erectum).  (Fig.  77.)  In  early  spring  children  often 
gather  bouquets  of  its  lurid,  purple  flowers  which  they  are  soon 

162 


FLY-FLOWERS 


Fig.  77.     Purple  Trillium.     Trillium  eredum 

A  fly-flower 


compelled  to  throw  away.  Since  the  blossoms  are  nectarless, 
they  are  visited  only  occasionally  by  flies  for  pollen.  Its  pene- 
trating characteristic  odor,  it  is  needless  to  say,  prevents  any  one 
from  making  such  a  mistake  in  the  case  of  the  skunk-cabbage. 
Within  each  spathe  or  leafy  hood  there  is  a  cluster  of  small, 

163 


THE   FLOWER  AND   THE   BEE 

perfect  flowers  attractive  to  flies.  The  disagreeable  odor  might 
be  supposed  to  be  repellant  to  bees,  but  sometimes  in  early 
spring  large  numbers  of  them  gather  pollen  from  this  source 
for  brood-rearing.  The  water-arum  {Calla  palustris),  a  plant 
growing  in  cold  bogs,  has  a  handsome  white  spathe,  but  the 
nauseous  scent  places  it  among  fly-flowers.     (Fig.  78.) 

Among  flowers  with  unpleasant  odors  the  saxifrages  are 
highly  interesting,  not  because  flies  are  the  most  numerous 
visitors,  but  because  the  white  corolla  is  covered  with  many- 
colored  dots.  The  white  petals  of  the  round-leaved  saxifrage 
{Saxifraga  rotundifolia)  are  sprinkled  with  round  dots,  the  outer 
of  which  are  intense  purple  red  and  the  inner  yellow.  The  snow- 
white  flower  of  the  star  saxifrage  (S.  siellaria)  are  beset  with 
purple  dots  and  adorned  with  two  orange-yellow  spots.  >Sa.r2*- 
fraga  hryoides  is  white  with  many  shining  yellow  dots.  (Fig. 
79.)  The  large  golden-yellow  flowers  of  8.  aizoides  are  marked 
with  numerous  orange-red  dots,  and  are  visited  by  85  different 
species  of  flies;  all  of  these  spotted  flowers  are  indeed  very 
frequently  visited  by  flies.  Mueller  believed  that  the  dots 
attracted  the  attention  of  flies  more  than  of  other  insects. 

There  is  another  group  of  fly-flowers,  the  pitfall-flowers, 
which  rely  partly  on  deceptive  odors  and  colors,  and  partly  on 
pitfalls,  which  are  veritable  prison-traps — often  death-traps— to 
various  unwary  flies.  The  spotted  arum  {Arum  macidatum)  of 
Europe  is  a  prison-flower  and,  like  all  the  Aroids,  has  an  offensive 
odor.  The  spathe,  which  is  broad  above,  is  constricted  in  the 
middle  into  a  neck,  below  which  there  is  a  bulbous  cavity  com- 
pletely ensheathing  the  lower  part  of  the  club-shaped  flower- 
stalk,  or  spadix.  In  the  neck  or  entrance  to  the  chamber  there 
is  on  the  spadix  a  ring  of  bristles  with  the  points  inclined  down- 
ward, a  little  below  this  a  band  of  staminate  flowers,  then  an- 
other ring  of  hairs,  beneath  which  are  the  pistillate  flowers. 

164 


Fig.  78.     Water-Arum.     Calla  palvstris 
Exhales  a  disagreeable  odor  attractive  to  flies.     Grows  in  wet  swamps 


THE  FLOWER  AND   THE  BEE 

The  pistillate  flowers  which  secrete  nectar  mature  first,  and  the 
incurved  hairs  permit  the  midges  {Ceratopogon)  which  effect 
pollination  to  pass  easily  down  to  them,  but  prevent  their  re- 


FiG.  79.     Mountain  Saxifrage.     Saxifraga  hryoides.     (After  Mueller) 

The  petals  are  covered  with  numerous  dots  or  spots,  which  Mueller  believed  to  be  attractive  to 
flies,  which  visit  the  flowers  in  large  numbers.  A,  B,  and  D  represent  the  flower  in  the 
first  stage,  when  the  anthers  mature,  but  the  stigmas  remain  unreceptive;  C  represents  the 
second  stage,  when  the  stigmas  are  mature  and  the  anthers  have  withered  and  fallen  away 


turn.  The  lowest  ring  of  hairs  withers  first,  permitting  the 
midges  to  come  up  to  the  staminate  flowers,  where  they  be- 
come covered  with  pollen,  then  the  upper  ring  of  hairs  withers 
and  the  midges  are  free  to  fly  away.  As  many  as  a  thousand 
midges  may  be  imprisoned  in  a  single  spathe.     (Fig.  80.) 

166 


FLY-FLOWERS 


To  the  same  arum  fam- 
ily, or  Aracecp,  belongs 
jack-in-the-pulpit,  also 
called  Indian  turnip  from 
the  shape  of  its  root  {Ari- 
soema  triphyllum).  It  is  a 
pit  fall -flower.  It  flourishes 
in  wet  swamps  and  my 
observations  were  made 
while  standing  up  to  my 
ankles  in  water  and  sur- 
rounded by  a  cloud  of  mos- 
quitoes, from  which  a  veil 
gave  me  protection.  The 
stamina te  and  pistillate 
flowers  are  on  different 
plants.  The  staminate  are 
much  the  smaller,  being 
only  6  or  7  inches  tall, 
bloom  first,  and  soon  pe- 
rish. The  pistillate  or  fer- 
tile plants  are  much  larger, 
often  2  feet  tall.  The 
spathe  is  dark  purple 
striped  longitudinally  with 
white,  and  ensheathes  a 
club-shaped  stalk  or  spadix. 

Fig.  80.     Arum. 
Arum  conocephaloides 

A  prison-flower.     To  show   the   arrange- 
ment of  the  small  flowers  the  front  of 
the  spathe  is  removed.     On    the  low- 
est part  of  the  spadix,  or  club,  are  the  pistillate   ("female")  flowers,   above  them  the  first 
ring   of   bristles,    next    the   staminate    ("male")  flowers,  and  then  a  second  ring  of   bristles. 
At   the   bottom  of   the   cavity  are  a  number  of  midges  (Ceratopogon),  whose  escape  is  pre- 
vented by  the  stiff  reflexed  bristles  of  the  lower  ring.     (After  Kerner) 

167 


THE  FLOWER  AND  THE   BEE 

which  bears  near  its  base  several  whorls  of  small,  naked 
flowers,  while  its  apical  end  is  arched  over  the  "pulpit"  to 
exclude  rain.  There  is  a  small  orifice  at  the  base  of  the 
spathe,  where  one  edge  overlaps  the  other,  which  serves  for 
the  purpose  of  drainage.     (Figs.  81  and  82.) 

The  inner  side  of  the  spathe  is  smooth,  shining,  and  very 
slippery,  far  more  highly  polished  than  the  outside.  When 
little  moth-like  flies  of  the  genus  Psychoda  rest  on  this  polished 
surface  they  are  unable  to  gain  a  foothold  and  fall  into  the 
chamber  below.  There  for  a  time  they  are  held  prisoners, 
since  they  cannot  climb  the  smooth  walls  or  the  equally  smooth 
base  of  the  spadix.  The  staminate  flowers  are  visited  first, 
since  they  bloom  first.  As  the  spathes  wither,  their  inner  sur- 
faces relax  and  become  rougher,  enabling  the  little  visitors,  now 
loaded  with  pollen,  to  escape  and  fly  to  the  pistillate  plants. 
The  spathes  of  the  latter  wither  less  promptly,  but  from  the 
point  of  view  of  the  "jacks"  this  is  of  little  consequence, 
since  pollination  has  been  effected;  but  it  is  fatal  to  many  of 
the  flies  w^hich,  unable  to  escape,  perish  in  the  chamber. 
The  arum  family  includes  many  tropical  forms,  like  the 
calla-lily;  about  the  pollination  of  most  of  these  very  little  is 
known  and  undoubtedly  many  remarkable  facts  await  dis- 
covery. 

The  peculiar-shaped  Dutchman 's-pipe  {Aristolochia  sipho) 
is  pollinated  in  a  manner  very  similar  to  that  of  jack-in-the- 
pulpit;  but  the  flowers  are  perfect,  i.  e.,  contain  both  stamens 
and  pistils.  The  calyx  hangs  downward,  is  about  an  inch  and 
a  half  long,  bent  like  the  letter  S,  constricted  in  the  middle, 
with  the  bowl-end  of  the  pipe  narrowed  at  the  throat  and  very 
smooth  within.  After  they  have  once  entered  this  tubular 
passageway  small  flies  are  unable  to  fly  or  creep  out  until  the 
calyx  withers.     (Fig.  83.) 

168 


Fig.  82.     Jack-In-the-Pulpit.     Ariscema  triphyllum 
Spathe  or  ensheathing  leaf  of  pistillate  flowers  opened,  showing  fertile  flowers  at  base  of  spadix 


FLY-ILOWERS 

Among  the  Diptera  the  family  which  most  frequently  visits 
flowers  and  is  of  the  most  importance  in   jwllination  are  the 


Fig.  83.     Dutchman' s-Pipe.     Aristolochia  Sipho 
A  fly-flower 

hover-flies  or  Syrphidw.  They  feed  on  both  pollen  and  nectar, 
and  are  found  on  many  different  species,  their  long  tongues  en- 
abhng  them  to  reach  the  nectar  in  many  bee-flowers.  There 
are  several  small  flowers  adapted  to  pollination  by  the  hover- 

171 


THE   FLOWER   AND   THE   BEE 

flies,  the  most  common  being  the  speedwells,  tender  little  herbs 
of  the  genus  Veronica,  which  grow  in  our  gardens,  lawns,  and 
meadows.  When  June  is  a  wet  month  the  thyme-leaved  speed- 
well {Veronica  serpyUifolia)  is  abundant.  The  white  or  pale- 
blue  petals  are  marked  with  deeper  purple  Hues  leading  to  the 
nectar;  the  corolla- tube  is  yellow  and  the  throat  is  fringed  with 


Fig.  84.     Speedwell.     Veronica  Chamcpdrys 

A  syrphid-fly  flower.     A,  flower  seen  from  the  front;  B,  the  same  with  the  stamens  placed 
together;  C,  the  same  with  a  syrphid  fly  sucking  nectar.     (After  Mueller) 


hairs  to  exclude  water.  (Fig.  84.)  There  are  only  two  sta- 
mens, one  on  each  side  of  the  flower,  and  a  single  pistil  in  the 
centre,  all  three  of  which  taper  at  the  base  so  that  they  bend 
easily.  W'hen  a  syrphid  fly  visits  one  of  these  flowers,  the 
stigma  rests  against  the  under-side  of  its  body  while  the  feet 
grasp  the  stamens  and  draw  them  also  beneath  it,  where  they 
leave  a  part  of  the  pollen.  Self-pollination  may  be  prevented 
in  some  species  by  the  stigma  maturing  before  the  anthers,  but 
in  the  thyme-leaved  speedwell  the  anthers  may  deposit  pollen 
directly  on  the  stigma. 

The  syrphid  flies  are  very  common  visitors  to  golden-yellow 
flowers,  like  the  buttercup  and  marsh-marigold,  and  Mueller, 
observing  that  they  often  poised  before  them  a  few  seconds  be- 

172 


FLY-FLOWERS 

fore  darting  down  to  suck  nectar  or  eat  i)ollen,  thought  that  the 
bright-yellow  coloration  must  afford  these  flies  an  a\sthetic 
pleasure.  But  more  recently  Plateau  has  shown  that  this  is 
merely  a  habit  of  flight,  and  that  the  hover-flies  jioise  on  the 
wing  in  the  same  way  before  green  leaves,  green  flowers,  green 
fruits,  and  green  and  brown  stems,  or  even  before  a  cane,  or 
a  marble,  or  the  human  finger.  When  a  finger  was  gently  inter- 
posed between  a  fly  and  a  flower,  the  fly  remained  in  a  fixed 
attitude  as  before  and,  when  the  finger  was  slowly  moved  away, 
followed  it. 

Many  syrphid  flies  closely  resemble  bees  and  wasps,  and  can 
be  distinguished  from  them  with  diflSculty  when  on  the  wing. 
Field-collectors  occasionally  catch  them  and  send  them  away  as 
wasps.  By  some  naturalists  this  similarity  of  form  and  flight 
is  regarded  as  a  case  of  protective  resemblance,  by  others  as 
an  accidental  convergence  in  likeness.* 

No  one  can  long  observe  flowers  without  meeting  with  the 
bee-flies  {Bomhyliidw),  which  both  when  flying  and  at  rest  are 
often  mistaken  for  bees.  They  feed  on  nectar,  but  not  on 
pollen.  The  species  of  Bomhylius  are  densely  clothed  with 
silky  hair  and  both  in  movement  and  appearance  suggest 
small  moths.     The  long  proboscis  points  directly  forward,  and 

*  An  amusing  illustration  recently  occurred  in  the  experience  of  the  writer 
showing  how  easily  certain  flies  may  be  mistaken  for  honey-bees.  A  prominent 
local  official,  accustomed  to  observe  carefully,  told  me  how  his  wife  had  called 
his  attention  to  the  presence  of  many  bees  on  a  window  of  a  shed  chamber. 
He  related  how  after  putting  on  an  overcoat  and  protecting  his  face  and  hands, 
he  had  finally  driven  them  outdoors. 

"Now,"  he  inquired,  "how  did  they  get  there?" 

"They  were  not  bees  at  all,"  I  replied,  "but  flies.  If  you  will  examine  them 
carefully  you  will  find  that  they  have  only  one  pair  of  wings." 

Naturally  he  was  nuicli  astonished  at  this  statement;  but  some  days  later 
he  brought  me  two  of  the  insects  in  a  bottle.  They  proved  to  be,  as  I  had 
expected,  syrphid  flies  belonging  to  the  species  Eristalis  tenax,  often  found  on 
flowers. 

173 


THE   FLOWER   AND   THE   BEE 

the  flies  dart  swiftly  about  and  poise  on  the  wing  when  sucking, 
in  the  same  manner  as  the  hawk-moths. 

In  the  Alps  bee-flies  were  observed  by  Mueller  to  visit  three 
times  as  many  red,  violet,  and  blue  flowers  as  yellow  and  white 
ones.  But  in  Wisconsin  Graenicher's  observations  show  nearly 
the  opposite  result,  "  in  other  words,  more  than  twice  as  many 
white  and  yellow  flowers  have  received  the  attention  of  these 
flies  as  red,  purple,  or  blue  ones."  In  reply  to  an  inquiry  of 
the  writer's  as  to  how  he  accounts  for  Mueller's  results,  he 
replies  that  it  may  be  explained  by  a  larger  number  of  red  and 
blue  flowers  in  the  Swiss  flora  than  in  that  of  Wisconsin.  He 
also  calls  attention  to  the  curious  fact  that  during  seven  years 
in  Germany  Bombylius  discolor  was  observed  to  prefer  the 
flowers  of  the  lungwort  {Pulmonaria  officinalis)  to  those  of  any 
other  plant,  visiting  other  flowers  only  in  the  case  of  necessity. 

The  dance-flies  (EmpididoB) ,  which  may  often  be  seen  near 
running  brooks  dancing  in  mid-air  beneath  the  foliage  of  the 
trees,  have  long  tongues,  and  resort  to  many  flowers  for  nectar. 
I  shall  long  remember  the  fair  June  afternoon  spent  in  collecting 
the  visitors  of  the  twinflower  {LinnoBa  horealis).  In  an  open 
grove  of  tall  hemlocks  a  large  bed  of  this  trailing  evergreen  vine 
was  pink  with  nodding  blossoms.  (Fig.  85.)  The  flowers, 
which  exhale  a  sweet,  vanilla-like  fragrance,  are  borne  in  pairs 
at  the  summits  of  elongated  peduncles.  The  inverted  position 
of  the  flowers  excludes  the  rain.  The  nectar  is  secreted  at  the 
base  of  the  corolla,  on  the  lower  side  of  which  there  is  a  yellow 
marking  or  honey-guide.  Within  the  corolla  are  many  inter- 
crossing hairs  which  shut  out  small,  useless  flies,  which  I  have 
seen  vainly  seeking  an  entrance.  During  the  afternoon  I  col- 
lected eight  visitors,  all  of  which  were  found  on  examination 
to  belong  to  a  single  species  of  dance-fly  {Empis  rufescens). 
Other  observations  show  that  this  fly  is  the  only  pollinator  in 

174 


Fig.  85.     Twinflower.     LinnxEa  horealis 

A  fly-flower 


Fig.  86.     Common  Milkweed.     Asclepias  syriaca 

A  pinch-trap  flower 


FLY-FLOWERS 

this  locality,  and  that  the  twiiiflower  is  an  Empis  flower.  The 
males  of  the  dance-flies  live  wholly  on  flowers,  but  the  females 
are  partly  predaceous. 

The  milkweeds  are  pinch-trap  flowers,  which  in  their  remark- 
able pollinating  mechanism  rival  the  orchids.  The  pollen 
coheres  in  waxy  masses  called  pollinia,  which  by  means  of  an 
ingenious  clip-mechanism  are  clamped  to  the  legs,  tongues,  and 
antennae  of  flies  and  many  other  insects.  When  the  insect  flies 
to  another  flower  the  pollinia  come  in  contact  with  the  stigma, 
to  which  they  adhere  so  firmly  that  it  can  only  obtain  its 
liberty  by  snapping  the  connecting  bands.  Only  a  part  of  the 
species  of  Asclepias  are  pollinated  by  flies,  others  are  pollinated 
by  bees  and  butterflies.  It  is  not  uncommon  in  examining 
specimens  of  bees  to  find  one  or  more  of  these  clips,  which  are 
a  useless  burden  and  interfere  with  their  work,  on  their  legs  and 
antennse.  Gibson  states  that  an  English  bee-keeper  lost  thou- 
sands of  his  bees  from  the  effects  of  strings  of  these  clips,  which 
it  was  at  first  thought  were  a  fungous  growth.     (Fig.  86.) 

If  an  insect  caught  in  one  of  these  pinch-traps  is  not  strong 
enough  to  pull  away  the  pollinia  or  break  the  bands,  it  is  held 
a  prisoner  and  dies  a  lingering  death,  although  probably  a 
nearly  painless  one.  In  New  Zealand  the  flowers  of  Araiujia 
albens,  a  plant  introduced  from  the  Cape  of  Good  Hope,  which 
are  normally  pollinated  by  bumblebees,  catch  in  a  single 
night  hundreds  of  moths.  It  was  once  seriously  proposed  by 
an  economic  entomologist  to  employ  this  plant  in  the  extermi- 
nation of  the  codling-moth,  so  injurious  to  apples;  but  unfortu- 
nately the  co-operation  of  the  codling-moth  could  not  be  ob- 
tained, for  it  persistently  refused  to  visit  the  flowers  of  Araugia 
— another  illustration  that  the  well-laid  schemes  of  mice  and 
men — 

"  Gang  aft  a-gley." 
177 


CHAPTER    XI 
BEETLES  AND   FLOWERS 

THERE  are  no  beetle-flowers,  although  Delpino  believed 
that  the  flowers  of  magnolia  were  adapted  to  flower- 
beetles  of  the  genus  Cetonia.  It  would  be  much  better, 
indeed,  for  flowers  if  they  were  never  visited  by  beetles,  for  they 
accomplish  far  more  harm  than  benefit.  As  agents  in  pollina- 
tion they  are  of  little  significance.  The  enormous  devastation 
of  foliage  and  bloom,  the  absence  of  hairs  for  holding  pollen, 
the  consumption  and  waste  of  pollen  and  nectar,  the  inactivity 
of  many  species,  and  their  indefinite  manner  of  flight  are  factors 
which  greatly  reduce  their  value  as  pollen-carriers.  As  a  whole 
they  are  highly  destructive  to  vegetation  and  cause  annually 
much  loss  to  the  farmer,  fruit-grower,  and  florist.  The  cherry- 
weevil  often  destroys  the  crop  of  plums  and  cherries,  the  rose- 
chafer  strips  the  rose-bushes  of  both  flowers  and  foliage,  while 
the  blister-beetles  may  devour  large  areas  of  tomatoes  and 
potatoes  in  a  few  days. 

But  the  order  of  Coleoptera,  or  beetles,  is  of  special  interest, 
as  Mueller  has  pointed  out,  because  it  shows  so  clearly  how  the 
habit  of  anthophily,  or  flower-visiting,  has  arisen,  and  its  be- 
ginnings in  many  different  families,  genera,  and  species.  The 
length  of  time  which  has  elapsed  since  the  first  tendency  in  a 
family  toward  this  habit  was  manifested  is  indicated  by  the 
number  of  species  which  resort  to  flowers.  Where  a  whole 
family  is  dependent  on  a  floral  diet  the  epoch  was  more  remote, 
but  where  there  are  only  a  few  isolated  species  the  habit  has 
been  acquired  more  recently.     In  the  most  diverse  families 

178 


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THE  FLOWER  AND  THE  BEE 

single  species  have  become  habituated  to  a  diet  of  pollen  and 
nectar,  and  subsequently  in  some  cases  structural  changes  have 
been  developed  to  insure  greater  success  in  the  search  for  food. 

In  New  England  Frost  and  myself  have  collected  23'^2  species 
of  beetles,  belonging  to  127  genera  and  29  families  which  visit 
flowers.  This  is  probably  less  than  ^V  of  the  total  number  of 
described  species  in  this  region.  In  all  Europe  Knuth  has 
enumerated  only  434  anthophilous  beetles.  Why  is  it  that  so 
few  feed  on  pollen  and  nectar  .^  Their  habits  and  forms,  in  many 
instances,  answer  this  question;  many  are  predaceous  like  the 
tiger-beetles  and  ground-beetles,  or  are  scavengers  like  the 
rove-beetles;  others  are  nocturnal,  or  aquatic,  or  occur  chiefly 
on  the  ground,  lurking  beneath  stones  and  boards,  or  living  in 
the  nests  of  other  insects.  (Fig.  87.)  Many  flowers,  more- 
over, have  the  nectar  concealed  where  it  is  beyond  the  reach 
of  beetles,  which,  with  few  exceptions,  have  short  tongues. 

Beetles  are  usually  found  on  common,  open  flowers  with  the 
nectar  visible  or  nearly  visible,  as  the  cherries,  cornels,  shad- 
bush,  New  Jersey  tea,  and  goldenrods.  In  early  spring,  on  the 
white  flowers  of  the  shadbush  {Amelanchier  canadensis),  31 
species  have  been  taken,  the  choke-cherry  {Prunus  virginiana) 
(Fig.  88)  yielded  43,  the  chokeberry  {Pyrus  arbutifolia)  10,  and 
the  dense  panicles  of  small  white  flowers  of  the  meadow-sweet 
{Spiropa  salicifolia)  42,  while  the  flat-topped  cymes  of  the 
cornels  (Cornus)  attracted  38  species,  and  the  profusion  of 
flower-clusters,  which  convert  the  bushes  into  huge  bouquets, 
drew  to  the  viburnums  (Fig.  89)  the  phenomenal  number  of 
81  kinds.  In  New  England  on  the  New  Jersey  tea  {Ceanothus 
americanus)  13  species  were  captured,  but  in  the  warmer  climate 
of  Virginia,  Banks's  list  of  beetles  taken  on  the  Ceanothus  in- 
cludes 58  kinds.  Among  the  Compositoe  beetles  are  more  com- 
mon on  the  flowers  of  the  goldenrod  than  any  other  genus; 

180 


Fig.  88.     Choke-cherry.     Primus  virginiana 

The  flowers  are  great  favorites  with  beetles 


THE   FLOWER  AND   THE  BEE 

both  pollen  and  nectar  are  abundant  and  the  nectar  is  con- 
cealed in  floral  tubes  only  1^  mm.  long,  while  the  temperature 
of  the  dense  clusters,  which  offer  excellent  hiding-places,  is 
usually  a  little  above  that  of  the  atmosphere,  especially  at 
night.  The  asters,  thistles,  and  sunflowers  have  longer  floral 
tubes  and  are  visited  much  less  often  by  beetles.  There  are  a 
great  many  flowers,  as  in  the  mustard  and  carrot  families,  on 
which  only  one  or  two  species  of  Coleoptera  have  been  taken. 

In  the  flowers  enumerated  nectar  is  a  more  important  allure- 
ment than  pollen,  which  is  not  produced  in  large  quantities. 
But  many  flowers  which  are  totally  devoid  of  nectar  are  visited 
by  beetles  for  pollen.  The  staminate  cones  of  the  Scotch  pine 
(Pinus  sylvestris)  and  of  the  fir  attract  many  beetles,  while 
many  may  also  be  swept  from  grasses  where  they  devour  the 
anthers  as  well  as  the  pollen.  Beetles  are  likewise  common  on 
conspicuous  pollen-flowers  like  the  rose,  poppy,  and  St.-John's- 
wort,  and  at  times  entirely  strip  the  rose-bushes  of  both  flowers 
and  leaves.  The  frequency  with  which  beetles  resort  to  pollen- 
flowers  led  Knuth  to  conclude  that  they  prefer  pollen  to  nec- 
tar, but  if  this  were  universally  true,  genera  feeding  on  nectar 
alone,  such  as  Nemognaiha,  would  never  have  been  developed. 

Beetles  are  occasionally  taken  on  two-lipped,  or  bilabiate, 
flowers  with  the  nectar  deeply  concealed,  where  they  are 
either  searching  for  food  or  their  presence  is  accidental.  Al- 
though the  nectar  is  inaccessible,  it  is  often  possible  for  them 
to  obtain  pollen.  According  to  Kerner  many  small  beetles 
find  a  refuge  in  the  interior  of  gentian-flowers,  while  species 
of  Cetonia  remain  for  several  days  in  the  partially  expanded 
flowers  of  magnolia  feeding  on  the  sweet  juices  and  pollen. 
Carrion-beetles  are  sometimes  found  in  great  numbers  in  the 
ill-smelling  spathes  of  the  Aroids,  and  tubular  flowers  often 
provide  nocturnal  lodging  for  wayfarers  of  the  Coleoptera. 

18^2 


Fto.  89.     Slieepberry.     Jlhurnum  Lentago 
Visited  by  more  species  of  beetles  than  any  other  New  Eiiglaiiil  flower 


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BEETLES  AND   FLOWERS 

Many  beetles  pass  their  entire  life  on  a  single  plant  species. 
The  larvae  of  Donacia  piscatrix  mine  in  the  leaves  and  stems  of 
the  yellow  water-lily,  while  the  adult  beetles  flourish  within 
the  floating  flowers;  another  species  of  Donacia  attaclics  its 
cocoons  to  the  base  of  the  stems  of  the  marsh-marigold,  and 
when  the  flowers  open  they  emerge  and  climl)  the  stems  and  11  \e 
in  plenty,  half  bin-ied  among  the  stamens;  the  larvie  of  the  fa- 
miliar asparagus-beetle  eats  the  leaves  of  the  cultivated  aspara- 
gus, and  the  beetles  visit  the  flowers.     (Fig.  90,  No.  7.) 

The  blue-flag  beetle  {Mononychus  vulpeculus)  passes  its 
entire  life  on  the  blue  flag,  and  is  most  common  during  the 
blooming-time  of  the  flowers.  (Fig.  91.)  It  is  inactive  in  the 
bright  sunshine,  says  Needham,  and  will  dodge  around  the 
base  of  a  flower  like  a  squirrel  around  the  base  of  a  branch 
when  a  hand  approaches,  but  will  rarely  fly.  "With  its  beak 
it  sinks  a  shaft  in  the  nectariferous  tissue,  nibbles  a  little,  makes 
another  hole,  and  another,  and  another,  until  the  nectar  is  left 
flowing  from  many  punctures,  attracting  swarms  of  insects  of 
all  sorts."  In  one  instance  while  the  weevil  was  gnawing  a 
hole,  there  were  three  flies  facing  it  and  another  on  its  back, 
"crowding  one  another  like  pigs  around  a  trough."  The  eggs 
are  laid  in  the  seed-capsule,  the  larva'  feed  on  the  young  ovules 
until  they  undergo  their  transformation  into  beetles,  and 
finally  in  the  fall  the  bursting  of  the  capsule  sets  free  both  the 
weevils  and  the  seeds.     (Fig.  90,  No.  8.) 

The  blister-beetles  also  restrict  their  visits  chiefly  to  one 
kind  of  flower;  for  instance,  an  oblong,  dull-black  species 
(Epicaida  pennsylvanica)  is  much  more  commonly  found  on 
the  flowers  of  the  goldenrod  than  elsewhere.  At  times  the 
blister-beetles  appear  suddenly  by  bushels  and  destroy  in  a 
few  days  large  patches  of  potatoes  and  tomatoes.  The  larvae 
are  brood-parasites  on  bees,  grasshoppers,  and  other  insects. 

18.5 


THE   FLOWER  AND   THE   BEE 

When  they  first  hatch  they  are  active,  louse-hke  forms  called 
triangulins  because  each  leg  terminates  in  three  claws.  The 
eggs  are  laid  on  the  ground  near  the  stem  of  a  flowering  plant, 
and  as  soon  as  the  triangulins  are  out  of  the  egg  they  climb  to 
the  flowers,  where  they  wait  for  the  arrival  of  some  insect. 
(Fig.  90,  No.  5.) 

Unfortunately  for  them,  they  are  unable  to  recognize  their 
hosts,  and  jump  aboard  the  first  conveyance  that  comes  along, 
whether  it  is  a  bee  or  a  fly,  with  the  result  that  they  are  often 
carried  far  away  from  the  nests  they  are  seeking  to  reach. 
There  is  nothing  for  them  to  do  but  to  keep  on  trying  until  they 
either  die  from  exhaustion  or,  by  a  happy  chance,  lay  hold  of 
the  right  insect.  Hundreds  do  perish,  and  to  compensate  for 
this  loss  the  female  lays  some  2,000  eggs.  If,  however,  a  tri- 
angulin  is  carried  to  the  nest  of  a  host  bee  it  feeds  on  the  pol- 
len until  it  is  transformed  into  a  beetle.  The  adventures  of  a 
triangulin  are  analogous  to  those  of  a  grain  of  pollen.  Waste- 
ful as  is  this  method,  it  succeeds  much  better  than  would  seem 
possible. 

A  part  of  the  Coleoptera  are  sarcophagous,  or  flesh-eaters, 
and  a  part  are  plant -eaters,  or  phytophagous,  feeding  on  wood, 
sap,  leaves,  and  other  vegetable  matter.  The  first  group  is 
certainly  older  and  more  primitive  than  the  second,  while 
among  plant-eating  beetles  those  living  on  wood  (xylophagous) 
are  older  than  those  feeding  on  foliage  or  flowers.  Beetles 
living  on  pollen  and  nectar  are  the  most  recent  in  origin  of  all. 

The  Sarcophagous  Beetles  as  Flower-Visitors 

Carnivorous  families  of  beetles,  especially  where  they  live 
on  the  ground,  are  not  likely  to  visit  flowers.  None  of  the 
terrestrial    tiger-beetles    or   water-tigers,    both    of   which    are 

186 


Fig.  91.     Blue  Flag.     Iris  versicolor 


THE   FLOWER  AND   THE  BEE 

predaceous,  have  ever  been  observed  eating  pollen  or  nectar. 
Very  few  species  of  the  rove-beetles  {Staphylinidw) ,  which  also 
live  chiefly  on  the  ground,  are  ever  found  on  flowers,  although 
a  few  very  small  forms  (Anthobium)  devour  the  pollen  of  the 
red-berried  elderberry.  Among  the  ground-beetles,  or  Carabidcp, 
Lebia  is  the  only  genus  which  regularly  visits  flowers;  these 
small  green  beetles,  common  on  the  goldenrods,  feed  partially 
on  plant-lice  and  insect-eggs,  and  it  was  undoubtedly  the 
search  for  food  on  foliage  that  led  to  flower-visiting.  These 
great  families  show  how  difficult  it  is  for  flesh-feeding  species 
living  on  the  ground  to  become  anthophilous. 

The  lady-bugs  {Coccinellid(p)  are  common  on  foliage,  search- 
ing for  plant-lice,  or  Aphides,  and  consequently  they  not  in- 
frequently pass  over  to  flowers.  Their  short  legs  and  round 
forms  render  them  exceedingly  awkward  and  inefficient  visitors 
and  they  are  of  little  significance  in  pollination.  I  have  seen 
one  of  them  slip  backward  five  or  six  times  before  it  succeeded 
in  climbing  the  smooth  stem  of  a  flower  of  the  prickly  sarsa- 
parilla.  The  contents  of  their  stomachs  consists  chiefly  of 
pollen  and  spores.  A  part  of  the  dermestids,  so  destructive 
to  skins,  feathers,  and  woollen  carpets,  also  frequent  flowers 
for  pollen.  The  carpet-beetle  in  the  adult  stage  is  abundant 
on  the  flowers  of  the  currant  and  cherry.  Every  one  who  has 
picked  raspberries  has  met  the  little  white  larvae  of  another 
species  {Byhirus  unicolor),  which  infests  the  fruit,  while  the 
small,  brown  beetles  visit  the  flowers. 

The  familiar  fireflies  are  carnivorous  both  in  the  larval 
and  adult  stages,  but  as  the  beetles  are  common  on  the  bark 
and  fohage  of  shrubs  and  trees,  they  are  often  taken  on  flowers. 
Many  are,  however,  night-fliers.  Special  interest  attaches  to 
the  soldier-beetles  {Chauliognaihus) ,  one  of  the  few  genera  of 
the   Coleoptera  which   have   the   mouth-parts   lengthened   to 

188 


BEETLES  AND  FLOWERS 

enable  them  to  suck  nectar  more  easily.  The  soldier-beetle 
may  be  found  by  thousands  on  the  goldenrods,  New  Jersey  tea, 
linden,  and  wild  hydrangea.     (Fig.  90,  No.  4.) 

It  is  evident  that  carnivorous  beetles  which  seek  their  i)rey 
on  vegetation  are  much  more  likely  to  acquire  the  habit  of 
visiting  flowers  than  those  which  live  wholly  on  the  ground. 
In  general,  they  feed  more  freely  on  pollen  than  on  nectar, 
partly  because  it  is  more  easily  obtained,  and  partl3%  perhaps, 
because  it  resembles  in  its  composition  the  animal  food  to  which 
they  are  accustomed.  Most,  if  not  all  of  them,  have  acquired 
the  habit  of  visiting  flowers  independently  of  each  other. 

The  Phytophagous  Beetles  as  Flower-Visitors 

But  it  is  among  the  beetle  families,  which  both  in  the  larval 
and  adult  stage  feed  on  vegetable  substances,  that  the  habit 
of  visiting  flowers  has  become  most  important.  It  is  an  easy 
step  for  them  to  learn  to  live  on  floral  food,  although  from  a 
great  number  of  tubular  flowers  they  are  largely  excluded. 

The  click-beetles  {ElateridoB) ,  of  which  39  species  have  been 
taken  on  flowers  in  New  England,  live  under  bark,  or  bask  in 
the  sunshine  on  the  foliage  of  trees  and  herbage.  The  leaf- 
beetles  {ChrysomelidcF) ,  one  of  the  latest  families  to  be  evolved, 
are  of  small  or  medium  size  and  in  both  the  larval  and  adult 
stages  are  very  destructive  to  foliage.  It  is  only  by  the  ex- 
penditure of  much  time  and  labor  that  the  ravages  of  the  potato- 
bug  and  squash-bug  are  checked  annually.  It  is  impossible  for 
this  immense  family  to  depend  on  pollen  and  nectar  alone,  for 
the  flower -food  available  would  be  wholly  inadequate  to  their 
requirements;  but  many  species  are  occasional  visitors  to 
flowers. 

Another  great  family  of  beetles  are  the  Scarabseids,  which 

189 


THE   FLOWER   AND   THE   BEE 

take  their  name  from  the  genus  Scarabceus,  famous  in  art  and 
Egyptian  mythology.  They  are  partly  scavengers  and  partly 
leaf -chafers,  comparatively  few  visiting  flowers.  Armies  of 
rose-chafers  {M acrodactijlus  suhspinosus)  often  strip  rose-bushes 
and  other  shrubs  of  both  flowers  and  leaves  (Fig.  90,  No.  9), 
or  devour  the  blossoms  and  ruin  the  crop  of  grapes.  The  com- 
mon June-bugs  defoliate  trees,  and  on  a  warm  evening  the  noise 
of  their  wings  may  be  heard  for  a  long  distance.  In  these  war- 
like days  it  is  of  interest  to  recall  that  a  host  of  June-bugs 
once  put  British  soldiers  to  flight  near  Boston.  In  John  Trum- 
bull's epic  poem  "M'Fingal"  it  is  stated  that,  absurd  as  it 
may  seem,  it  was  a  fact  that  some  British  officers,  soon  after 
Gage's  arrival  in  Boston,  while  walking  on  Beacon  Hill,  shortly 
after  sunset  were  greatly  frightened  by  the  sound  made  by 
flying  June-bugs,  which  they  took  to  be  the  sound  of  bullets. 
They  left  the  hill  in  great  haste,  alarmed  their  camp,  and 
later  wrote  home  to  England  terrible  accounts  of  being  shot  at 
with  air-guns. 

"No  more  each  Britisli  Colonel  runs 
From  whizzing  beetles  as  air-guns; 
Think  horn-bugs  bullets,  or  through  fears 
Musketoes  takes  for  musketeers." 

The  snout-beetles  or  weevils  (RhyncopJiora),  an  immense 
group  highly  injurious  to  vegetation,  seldom  visit  flowers,  and 
as  pollinators  are  of  little  importance.  The  long  snout  is  used 
in  excavating  little  pits  in  which  they  lay  their  eggs. 

The  wood-borers  {Cerambycidce),  on  the  contrary,  rank  first 
in  importance  as  flower-visitors  among  the  families  of  the 
Coleoptera.  They  are  present  in  great  abundance  on  densely 
clustered  small  flowers,  such  as  New  Jersey  tea  (Ceanothus), 
viburnum,  the  cornels,  spiraea,  and  chokeberry.     They  prefer 

190 


BEETLES  AND   FLOWERS 

nectar,   which    their    mouth-parts,   fringed   with    hair,   enable 
them  to  hck  up  easily.    As  the  grubs  are  tree-borers,  the  beetles 


Fig.  92.     Beetles  with  a  Tongue  Resembling  That  of  a  Butterfly 
Belonging  to  the  Genus  Nemognatha 

Among  the  100,000  or  more  described  species  of  beetles,  only  two  genera  {Nemognatha  and 
Gnathium)  have  a  long  sucking-tongue 


are  most  common  on  flowers  in  or  near  woodlands,  while  on 
the  same  flowers  a  mile  away  they  may  be  entirely  absent. 
(Fig,  90,  Nos.  1,  2,  and  3.)     The  elongated  head  and  prothorax 

191 


THE   FLOWER   AND   THE   BEE 

of  many  wood-boring  beetles  has  been  eonsidered  an  adapta- 
tion for  obtaining  nectar;  but,  as  the  abdomen  is  also  long  and 
narrow,  their  cylindrical  form  has  been  determined  more  prob- 
ably by  their  habit  of  gnawing  burrows  in  solid  wood,  just  as 
the  elongated  front  of  the  head  of  the  weevils  has  resulted  from 
the  excavating  of  little  pits  in  Avhich  to  lay  their  eggs. 

Among  the  anthophilous,  or  flower-visiting  Coleoptera,  the 
two  most  remarkable  genera  are  Gnaihium  and  Nemognatha,  of 
the  blister-beetle  family  (Meloidcc),  which  have  a  slender  suc- 
torial tongue,  like  that  of  a  butterfly,  except  that  it  cannot  be 
coiled  up.  It  varies  greatly  in  length  in  the  different  species, 
attaining  in  one  instance  a  length  of  11  mm.  Both  genera 
live  wholly  on  nectar,  and  they  thrust  this  tongue  in  and  out 
of  tubular  flowers  with  the  precision  and  rapidity  of  bees.  It 
may  seem  strange  that  other  beetles  have  not  acquired  a  suc- 
torial tongue  since  it  is  common  to  all  the  butterflies  and  moths, 
but  the  Coleoptera  did  not  begin  visiting  flowers  till  late  in  the 
history  of  their  development,  and  they  are  dependent  on  nectar 
for  food  to  such  a  small  extent  that  variations  in  this  direction 
would  not  be  likely  to  be  preserved  in  most  cases.     (Fig.  92.) 

The  primitive  Coleoptera  lived  largely  upon  the  ground,  but 
as  they  learned  to  search  for  their  prey  on  trees  and  herbage, 
they  gradually  began  to  visit  flowers.  They  have  never,  how- 
ever, been  of  much  importance  in  flower-pollination,  and  floral 
structure  has  not  been  modified  in  any  way  as  the  result  of 
their  visits.* 

*  A  complete  list  of  the  known  anthophilous  Coleoptera  of  New  England  with 
a  description  of  the  flowers  visited  by  them  will  be  foimd  in  two  papers  by  the 
author,  prepared  with  the  co-operation  of  Mr.  C.  A.  Frost,  published  in  Psyche; 
A  Journal  of  Entomology,  vol.  22,  No.  3,  pp.  67-84;  No.  4,  pp.  109-117,  1915. 


192 


CHAPTER  XII 
POLLEN-FLOWERS 

NOT  long  ago  a  popular  youths'  periodical  published  on 
its  children's  page  a  large  picture  of  a  climbing-rose 
bush  from  which  a  swarm  of  honey-bees  was  repre- 
sented as  gathering  nectar.  Beneath  the  bush  was  a  still- 
house  from  which  ran  tubes  to  every  flower,  xlfter  the  nectar 
had  passed  through  a  refining  apparatus  the  bees  were  depicted 
as  bottling  and  carting  the  honey  away.  It  was  an  ingenious 
and  amusing  conceit,  but  unfortunately  the  roses  do  not  yield 
nectar,  and,  alas !  there  is  no  such  thing  as  rose-honey.  The 
rose  has  proven  a  veritable  thorn  in  the  flesh  to  both  artists  and 
poets. 

One  of  our  popular  poets  sings  of  the  honey-bee: 

*'He  harries  the  ports  of  the  hollyhocks, 
And  levies  on  poor  sweetbrier; 
And  drinks  the  whitest  wine  of  phlox, 
And  the  rose  is  his  desire." 

Not  at  all.  "He"  (the  worker-bee  is  an  undeveloped  fe- 
male, and  the  drones  do  not  visit  flowers)  does  nothing  of  the 
kind,  for  the  rose  is  nectarless  and  the  phlox  is  a  butterfly- 
flower.  Before  describing  flowers  the  poet  would  do  well  to 
study  them  more  closely. 

Even  bee-keepers,  who  should  know  better,  very  generally 
believe  that  bees  gather  nectar  from  the  wild  roses.  "There 
has  been  some  discussion  of  late,"  writes  one  of  them,  "as  to 
whether  bees  get  any  honey  from  roses.  I  believe  that  I  have 
seen  them  working  very  freely  on  wild  roses,  and  I  see  no  good 
reason  why  roses  should  not  yield  honey,  as  they  belong  to  the 

193 


THE   FLOWER  AND   THE   BEE 

same  family  as  the  apple,  pear,  plum,  cherry,  and  raspberry. 
If  one  species  in  a  family  yields  nectar  we  may  expect  that  they 
will  all  do  so."  This  may  seem  probable,  but  it  is  not  the  fact. 
In  the  buttercup  family  the  buttercups,  columbines,  and  lark- 
spurs all  secrete  nectar,  but  the  anemone  and  hepatica  do  not. 
Most  species  in  the  figwort  family  (Scrophulariacecp)  yield  nec- 
tar, but  some  mulleins  do  not.  In  the  honeysuckle  family 
{Caprifoliacece)  the  honeysuckles  and  viburnum  are  nectarif- 
erous, but  the  elderberries  are  pollen-flowers.  Some  orchids 
secrete  nectar,  others  do  not.  In  the  nightshade  family 
{Solanacecp)  the  nightshade  is  nectarless,  but  the  ground- 
cherry  {Physalis)  yields  nectar. 

Although  the  handsome  flowers  of  the  rose  are  devoid  of 
nectar,  they  contain  such  an  abundance  of  pollen  that  they  still 
attract  a  great  many  visitors,  as  honey-bees,  bumblebees,  leaf- 
cutting  bees,  mason-bees,  ground-bees,  as  well  as  flies  and 
beetles.  Three  or  four  little  coal-black  bees  of  the  genus 
Prosopis,  which  look  like  ants,  may  be  seen  on  a  single  rose 
eating  pollen;  but  they  are  so  small  that  they  are  of  little  use 
in  pollination.  But  large  bees,  like  the  bumblebees,  can  hardly 
fail  to  come  in  contact  with  the  stigmas,  and  thus  are  the  most 
efficient  pollinators.     (Fig.  93.) 

Conspicuous  flowers  pollinated  by  insects,  which  do  not  se- 
crete nectar,  are  called  pollen-flowers.  Common  pollen- 
flowers  are  the  Hepatica,  many  species  of  Clematis  and  Anemone, 
the  bloodroot,  California  poppy,  the  elders,  rock-roses,  loose- 
strifes, St. -John's -worts,  poppies,  nightshades,  and  species  of 
mullein.  Spiraea  and  Thalidrum. 

While  a  part  of  the  species  of  mullein  {Verhascum)  secrete 
a  little  nectar,  others  are  nearly  or  wholly  nectarless.  The 
stamens  are  clothed  with  violet-colored  hairs,  which  afford  a 
good  foothold   to  small  bees   and  hover-flies  while  they   are 

194 


POLLEN-FLOWERS 


Fig.  93.     Wild  Rose.     Rosa  humUis 
A  pollen-flower 


gathering  or  eating  the  pollen.  The  mulleins  appear  to  be  in 
a  transition  stage.  They  have  nearly  ceased  to  secrete  nectar, 
and  have  become  dependent  on  their  supply  of  pollen  to  attract 
insects,  thus  strongly  suggesting  that  all  pollen-flowers  earlier 
in  their  history  yielded  nectar.     (Fig.  94.) 

195 


THE  FLOWER  AND  THE  BEE 

The  scarlet  hue  of  the  poppy  has  been  said  to  repel  bees, 
but  bee-keepers  who  have  seen  their  bees  freely  visiting  these 
gaudy  flowers  do  not  need  to  have  this  assertion  refuted. 
(Figs.  95  and  96.)  Although  an  acre  of  poppies  would  not 
produce  an  ounce  of  honey,  there  are  occasional  reports  of 
bees  being  stupefied  by  gathering  nectar  from  poppy  blossoms 
and  lying  about  on  the  ground  unable  to  fly;  but  all  such 
stories  are  mythical.  The  hundreds  of  large,  beautiful,  purple 
flowers  displayed  by  the  garden-clematis  (C  Jachnanni) 
contain  no  nectar,  and  bees  visit  them  only  occasionally  to 
gather  the  scanty  supply  of  pollen.  But  the  wild  clematis 
(C  virginiana)  produces  a  profusion  of  small  white  flowers 
which  are  nectariferous.  The  yellowish-green,  dilated  fila- 
ments act  as  nectaries  and  secrete  small  drops  of  nectar  on 
their  inner  surface.  With  age  the  filaments  lengthen  and  turn 
white  and  then  cease  to  produce  nectar.  Thus  it  is  only  the 
young  blossoms  which  offer  a  sweet  booty  to  their  guests. 
From  the  bright-yellow  flowers  of  the  common  loosestrife 
{Lysimachia  vulgaris)  a  little,  black,  solitary  bee  {Macropis 
ciliata)  gathers  its  entire  supply  of  pollen  for  brood-rearing. 
(Fig.  97.) 

The  poppy  and  the  rose  produce  a  bountiful  store  of  pollen, 
but  otherwise  remain  passive,  making  no  effort  to  place  it  on 
the  visiting  insect.  On  the  other  hand,  there  are  many  highly 
specialized  pollen-flowers  which  possess  varied  devices  for 
bringing  the  pollen  in  contact  with  the  visitor.  In  the  purple 
nightshade  {Solanum  Didcamara),  one  of  the  simpler  forms, 
the  anthers  unite  in  a  cone  around  the  style  and  a  shower  of 
pollen  falls  from  pores  in  their  tips,  when  a  bee  inserts  its  tongue 
between  them.  In  the  pulse  family  {Leguminosw)  there  are 
a  number  of  species,  which  although  they  have  lost  the  power 
of  secreting  nectar  still  find  the  pumping  and  explosive  mecha- 

196 


Fig.  94.     Mullein.     Verbascum  Thapsus 
A  pollen-flower 


THE  FLOWER  AND  THE  BEE 


Fig.  95.     Red  Poppy.     Papaver  Rhoeas 
A  pollen-flower 

nisms,  previously  acquired,  very  useful.  In  the  flowers  of  the 
tick-trefoil  {Desmodiiim),  which  are  pollinated  by  bumblebees, 
the  stamens  are  held  under  tension  and  shed  their  pollen  while 
enclosed  in  the  keel.  When  a  bumblebee  alights  on  the  wings, 
the  anthers  are  released  and  the  elastic  filaments  project  the 
pollen  up  in  the  air,  as  though  there  had  been  a  shght  explosion. 

198 


POLLEN-FLOWERS 


Fig.  96.     Purple  Poppy.     Papaver  somniferum 

A  pollen-flower 


There  is  provision  for  only  a  single  visit,  since  the  entire  stock 
of  pollen  is  exhausted  at  once.  Male  bumblebees,  which  have 
no  occasion  to  collect  pollen,  do  not  visit  these  flowers.  The 
flowers  of  the  lupine  {Lupinus),  another  genus  of  the  pulse 
family,  are  also  nectarless.  Here  the  pollen  is  expelled  by  a 
piston  mechanism.     The  five  outer  stamens,   after  discharg- 

199 


THE  FLOWER  AND   THE  BEE 

ing  their  pollen  inside  the  keel,  wither  up;  while  the  five  inner 
stamens  act  as  a  piston  and  push  out  the  pollen  during  an 
insect  visit.  The  blue  lupine  (Lupinus  subcarnosus) ,  the  State 
flower  of  Texas,  w^hich  carpets  large  areas  of  land  w^ith  its  hand- 
some blue  flowers,  is  visited  by  a  great  company  of  honey- 
bees for  pollen. 

In  some  pollen-flowers  there  is  a  curious  division  of  labor 
among  the  stamens,  as  in  Cassia  and  Heeria.  A  part  of  the 
anthers,  called  nutritive  anthers,  are  designed  to  furnish  food 
to  the  visitors  and  are  a  conspicuous  bright  yellow;  while  a 
part  reserved  for  pollination  are  an  inconspicuous  green  or  the 
color  of  the  petals.  In  the  mud-plantain  {Heteranthera  reni- 
formis)  there  are  two  short  stamens  with  golden-yellow  anthers, 
and  one  long  stamen  with  a  pale-blue  or  greenish  anther.  While 
the  bees  are  working  on  the  short  nutritive  anthers,  pollen  is 
deposited  on  their  bodies  by  the  long  reproductive  anthers. 

Pollen-flowers  display  every  shade  of  color,  as  white,  yellow, 
orange,  red,  scarlet,  pink,  purple,  and  blue.  The  differently 
colored  varieties  of  the  Hepatica,  which  may  be  found  bloom- 
ing in  May,  amid  the  brown  leaves  fallen  from  the  trees  during 
the  season  previous,  are  well  described  by  Burroughs: 

"Sometimes  she  stands  in  white  array, 
Sometimes  as  pink  as  dawning  day. 
Or  every  shade  of  azure  made, 

And  oft  with  breath  as  sweet  as  May." 

This  variety  in  coloration  is  good  evidence  that  the  pollen- 
flowers  were  once  nectariferous.  There  can  be  little  doubt 
that  at  some  time  in  their  past  history  they  all  yielded  nectar, 
and  that  subsequently  this  function  was  lost.  The  occurrence 
of  isolated  genera  of  pollen- flowers,  as  the  roses  in  the  rose 
family,  the  elderberries  in  the  honeysuckle  family,  and  the  tick- 

200 


POLLEN-FLOWERS 


Fig.  97.     Common  Loosestrife.     Steironema  ciliatum 
A  pollen-flower 

trefoils  and  lupines  in  the  pulse  family,  in  families  where  the 
majority  of  the  genera  yield  nectar,  admits  of  hardly  any  other 
explanation.  There  is  httle  difficulty  in  understanding  how  a 
flower  may  lose  the  power  of  secreting  nectar.  Flowers  from 
which  the  bee-keeper  in  one  region  derives  an  enormous  sur- 

201 


THE  FLOWER  AND  THE   BEE 

plus  of  honey  may  be  in  another  wholly  valueless.  In  the 
Rocky  Mountain  highlands  alfalfa  is  the  main  reliance  of  the 
apiarist  and  no  other  honey-plant  can  compare  with  it,  but 
east  of  the  Mississippi  River  it  is  in  most  locahties  totally  de- 
void of  nectar.  In  the  prairie  States  white  clover  is  easily 
the  foremost  honey-plant,  but  in  France  one  may  ride  for 
miles  and  not  see  a  bee  on  the  flowers.  The  flowers  of  the  vine 
are  in  many  places  nectarless,  but  in  others  are  reported  to  be 
nectariferous.  Thousands  of  pounds  of  buckwheat-honey 
are  annually  produced  in  New  York  State,  but  farther  west  it 
is  of  little  or  no  value.  The  flow  of  nectar  in  buckwheat  is 
intermittent;  in  the  morning  it  is  active  and  the  flowers  are 
diligently  visited  by  bees,  but  in  the  afternoon  it  ceases  entirely 
and  the  bees  remain  idle  in  the  hives.  During  the  latter  part 
of  the  day  there  is  a  great  sea  of  white,  fragrant  flowers  with 
hardly  a  bee  on  them.  The  secretion  of  nectar  is  evidently 
greatly  influenced  by  soil  and  climate,  and  probably  other 
factors,  so  that  the  loss  of  this  function  in  certain  plant  genera 
is  not  at  all  surprising. 

Wind-pollinated  flowers,  although  they  do  not  produce 
nectar,  cannot  be  regarded  strictly  as  pollen- flowers,  since 
they  rely  on  the  wind  for  pollination.  In  early  spring,  honey- 
bees, hard-pressed  to  obtain  pollen  for  brood-rearing,  often, 
however,  by  thousands  gather  pollen  from  the  alders,  hazel- 
nuts, elms,  hickories,  and  walnuts.  Later  in  the  season  they 
may  resort  to  the  spindles  of  Indian  corn  and  the  green  flowers 
of  the  ragweeds.  Flies  and  beetles  also  feed  on  the  pollen  of 
rushes,  grasses,  and  sedges. 


202 


CHAPTER  XIII 

IS    CONSPICUOUSNESS    AN    ADVANTAGE    TO 
FLOWERS? 

FLOWERS  usually  owe  their  conspicuousness  to  a  bright- 
colored  corolla,  as  the  rose  and  the  buttercup.  In  the 
absence  of  petals  the  calyx  may  become  bright  colored, 
as  in  the  clematis,  anemone,  marsh-marigold,  and  buckwheat; 
or  both  calyx  and  corolla  may  be  highly  colored,  as  in  the  col- 
umbines, larkspurs,  and  fuchsia.  The  catkins  of  the  willows 
are  rendered  very  conspicuous  in  early  spring  by  the  numerous 
yellow  and  red  anthers,  while  in  the  meadow-rue  the  white 
filaments  are  broad  and  petaloid.  The  small  leaves  or  bracts 
surrounding  the  flow^ers  are  also  frequently  brilliantly  col- 
ored. In  the  painted-cup  (Castilleja)  the  bracts  are  bright 
scarlet;  in  Monarda  media  they  are  purple,  and  in  the  bunch- 
berry  white  (Fig.  98),  while  in  the  Proteacece  of  Australia  the 
upper  foliage  leaves  are  blue. 

Again,  conspicuousness  may  be  secured  by  massing  small 
flowers  in  large  clusters  (Fig.  99),  or  by  their  production  in  great 
profusion.  A  single  bluet  is  visible  at  a  distance  of  only  a  few 
feet;  but  when  they  whiten  a  whole  hillside  they  form  a  part 
of  the  facies  of  the  landscape.  When  the  dandelions  bloom, 
whole  fields  become  a  bright  golden-yellow  in  some  New  Eng- 
land towns;  while  in  New  Jersey  large  districts  are  white  with 
daisy -blossoms,  but  unfortunately  not  for  the  harvest.  On 
the  prairies  of  Nebraska  the  ground-plum  presents  in  spring  a 
very  striking  appearance,  the  plants  forming  dense  masses 
of    reddish-blue    flowers.     In    North    Carolina,    Rhododendron 

203 


THE  FLOWER  AND   THE  BEE 


Fig.  98.     Bimcliberry.     Cormis  canadensis 
The  small  central  flowers  are  rendered  conspicuous  by  an  involucre  of  four  white  leaves 


maximum  and  Kalmia  latifolia,  or  mountain-laurel,  the  two 
handsomest  North  American  shrubs,  "are  seen  to  cover  tracts 
of  great  extent,  at  one  season  presenting  an  unbroken  land- 
scape of  gorgeous  flowers."  They  adorn  the  valleys  all  around, 
says  Asa  Gray,  in  one  of  his  letters,  in  immense  abundance  and 

204 


Fig.  99.     Sunflower.     Helianthus  annuus 
Conspicuousness  is  gained  by  the  large  size  of  the  head,  or  capitulum 


THE   FLOWER   AND   THE   BEE 

profuse  blossoming,  of  every  hue  from  deep  rose  to  white. 
Almost  equally  conspicuous  in  various  parts  of  the  country 
are  large  areas  brightly  colored  with  yellow  buttercups,  golden- 
rods,  sunflowers,  orange  hawkweeds,  purple  thistles,  and  blue 
lupines.  In  Texas  the  State  flower,  the  blue  lupine,  carpets 
the  ground  for  miles  with  innumerable  blue  flowers.  But 
nothing  in  this  world  can  surpass  in  beauty  or  lavish  abun- 
dance the  cloud-like  masses  of  bloom  displayed  by  the  great 
northern  apple-orchards. 

"England  has  her  furze-clad  commons,"  says  Wallace,  "her 
glades  of  wild  hyacinths,  her  heathery  mountainsides,  her 
fields  of  poppies,  her  meadows  of  buttercups  and  orchises — 
carpets  of  yellow,  purple,  azure-blue,  and  fiery  crimson,  which 
the  tropics  rarely  can  exliibit.  We  have  smaller  masses  of 
color  in  our  hawthorn  and  crab-trees,  our  holly  and  moun- 
tain-ash, our  broom,  foxgloves,  primroses,  and  purple  vetches, 
which  clothe  with  gay  colors  the  whole  length  and  breadth  of 
our  land.  They  are  characteristic  of  the  country  and  climate, 
they  have  not  to  be  sought,  for  they  gladden  the  eye  at  every 
step." 

Brilliantly  colored  flowers  usually  contrast  with  the  green 
foliage  of  trees,  or  of  herbaceous  plants,  or  with  the  grass. 
But  the  white  and  blue  hepaticas,  which  bloom  with  the  open- 
ing of  the  new  season,  have  for  a  background  the  sere  and 
brown  leaves,  fallen  from  the  trees  during  the  preceding 
autumn;  and  contrasting  with  the  dark  soil  in  dense  woods 
gleams  the  snow-white  Indian-pipe.  (Fig.  100.)  Flowers 
which  rest  upon  the  surface  of  the  water  are  often  white  or 
yeUow,  as  the  yellow  and  white  water-lilies.  Nocturnal 
flowers  are  also  generally  white  or  yellow,  since  purple  or  blue 
would  be  invisible  in  the  darkness  of  night. 

In  Europe  and  North  America,  and  in  all  lands  where  there 

206 


i^^y^t  4A  ^^  ^Hi 

^^^^^^^^^^^■1 

Fig.  100.     Indian-Pipe.     Monotropa  uniflora 

The  snow-white  parasitic  plants  contrast  strongly  with  the  dark  soil  of  the  woods  in  which 

they  grow 


THE   FLOWER  AND   THE   BEE 

is  an  insect  fauna  rich  both  in  species  and  individuals,  flowers 
display  an  infinite  number  of  brilliant  hues  and  delicate  shades 
which  surpass  the  power  of  the  artist  and  naturalist  to  de- 
scribe. There  is  a  wonderful  variety  of  bicolored,  tricolored, 
and  variegated  blossoms,  often  mottled  and  veined  in  end- 
less ways.  Not  only  are  the  prismatic  colors — red,  orange, 
yellow,  green,  blue,  and  violet — displayed  by  many  species 
with  a  profusion  of  intermediate  shades,  but  rarer  colors  like 
black,  brown,  scarlet,  crimson,  and  lurid  purple  are  not  unrepre- 
sented. Nature  has  tried  her  skill  as  a  colorist  in  the  metallic 
lustres  and  translucent  hues  of  minerals;  in  the  vivid,  living 
tints  of  corals  and  sea-anemones;  in  the  lights  and  shades  re- 
flected by  the  scales  of  the  butterflies'  wings;  and  in  the  bril- 
liant iridescent  plumage  of  birds;  but  nowhere  are  her  inex- 
haustible resources  in  chromatics  so  bountifully  displayed  as 
in  the  colors  of  flowers. 

A  flora  in  which  the  flowers  were  all  of  one  color  would  be 
at  a  great  disadvantage.  The  value  of  color  contrasts  is  evi- 
dent, for  they  enable  the  visitors,  more  especially  the  bees, 
easily  to  remain  constant  to  a  single  plant  species  in  collecting 
pollen  and  nectar.  If  they  were  to  visit  flowers  indiscriminately, 
much  pollen  would  be  wasted  and  much  time  and  effort  lost  in 
locating  the  nectar.  In  the  Alpine  flora  of  the  Tyrol,  in  the 
heights  above  the  tree-line,  there  is  no  spring  and  no  autumn — 
only  a  short  summer  following  a  long  winter.  All  the  flowers 
have,  therefore,  to  blossom  in  this  short  time.  "White  and  red, 
yellow  and  blue,  brown  and  green,"  says  Kerner,  "stand  in 
varied  combination  on  a  hand's  breadth  of  space.  Hardly  has 
the  snow  melted  than  there  appear  almost  simultaneously  the 
violet  bells  of  the  soldanellas  and  the  golden  flowers  of  the 
cinquefoil,  the  white  crowfoot  and  androsace,  the  red  silenes  and 
primulas,  the  blue  gentians  and  the  yellow  auriculas,  the  heaven- 

208 


IS  CONSPICUOUSNESS  AN  ADVANTAGE? 

blue  forget-me-not  and  the  yellow  violet,  as  well  as  the  saxi- 
frages, in  every  conceivable  color."  Such  a  meadow  in  Alaska, 
where  the  summers  are  equally  short,  is  well  described  by 
Burroughs : 

"Starred  with  flowers  of  every  hue. 
Gold  and  purple,  white  and  blue; 
Painted  cup,  anemone, 
Jacob's  ladder,  fleur-de-lis. 
Orchid,  harebell,  shooting-star. 
Crane's-bill,  lupine,  seen  afar; 
Primrose,  poppy,  saxifrage. 
Pictured  type  on  Nature's  page." 

According  to  a  well-known  principle  of  physics,  each  color 
appears  more  brilliant  in  contrast  with  other  hues  than  it 
would  if  viewed  alone.  This  can  be  easily  shown  by  a  simple 
experiment,  which  any  one  can  perform.  Cut  out  two  pieces 
of  red  paper,  each  two  inches  square.  Place  one  of  the  red 
squares  on  a  large  sheet  of  green  paper  and  the  other  red 
square  on  a  large  sheet  of  red  paper.  The  red  square  on  the 
green  paper  will  appear  so  much  more  brilliant  than  the  red 
square  on  the  red  paper  that  the  observer  will  have  difficulty 
in  believing  that  they  are  identical  in  hue.     (Figs.  101  and  102.) 

Is  this  beautiful  and  varied  display  of  coloration  by  flowers 
of  no  use.^  Has  it  no  more  significance  than  the  vivid  iri- 
descent hues  of  minerals  and  precious  stones  "^  Is  it  merely  an 
incidental  result  .^^  To  most  observers  it  has  long  seemed  self- 
evident  that  conspicuousness  is  a  manifest  advantage.  If 
insects  possess  a  well-developed  sense  of  vision,  bright  colors 
cannot  fail  to  be  of  benefit  to  them  as  well  as  to  flowers  by  en- 
abling them  easily  to  discover  isolated  blossoms  and  to  econ- 
omize time  by  being  faithful  to  single  plant  species.  No  argu- 
ment is  needed  to  prove  that  such  a  correlation  is  desirable, 

209 


THE   FLOWER  AND   THE   BEE 

and  that,  if  it  is  non-existent,  its  absence  registers  a  failure  on 
Nature's  part  to  make  the  most  of  an  opportunity. 

According  to  the  teachings  of  Sprengel,  Darwin,  and  Mueller, 


Fig.  101.     Bean.     Jlcia  Faba 

Color  contrast,  a  black  spot  on  the  wings  of  the  papilionaceous 
white  corolla 

and  most  other  flower-biologists,  the  bright  hues  of  flowers 
serve  as  signals,  or  flags,  to  attract  the  attention  of  insects 
living  on  pollen  and  nectar.  The  more  conspicuous  a  flower, 
or  flower-cluster,   the  better   are   its   chances   of   pollination. 

210 


Fig.  102.     Purple  Coneflower.     Echinacea  angiisti folia,  a 
Coreopsis.     Coreopsis  iinctoria,  b 

Color  contrast,  the  disk  flowers  and  the  lower  part  of  the  rays  are  brown-purple,  the  upper 
part  of  the  rays  yellow 


THE   FLOWER  AND   THE   BEE 

Many  colors  are  better  than  one,  since  the  flowers  are  rendered 
more  conspicuous  by  contrasts  with  each  other  as  well  as  with 
foliage,  and  insects  are  less  liable  to  visit  them  indiscriminately. 
The  various  floral  colors  have  been  evolved  by  the  selective 
agency  of  insects,  especially  bees,  which  are  able  easily  to  dis- 
tinguish between  them,  and  in  the  absence  of  visitors  flowers 
would  have  remained  green,  or  dull-colored,  similar  to  wind- 
pollinated  blossoms.  In  some  instances  Mueller  believed  that 
the  visitors  manifested  a  preference  for  certain  colors,  as  honey- 
bees for  blue,  butterflies  and  humming-birds  for  red,  hover- 
flies  for  yellow,  and  carrion-flies  for  lurid  purple;  but  in  the 
Hght  of  more  recent  investigations  it  may  be  doubted  whether 
insects  receive  more  pleasure  from  one  color  than  another. 
The  usefulness  of  floral-color  contrasts  is  sufficient  to  explain 
their  development  without  recourse  to  the  supposition  that  they 
afford  an  aesthetic  pleasure  to  insects. 

With  the  exceptions  of  the  criticisms  of  Bonnier,  in  1879, 
Mueller's  doctrine  remained  almost  universally  unquestioned 
until  1895,  when  Felix  Plateau,  of  the  University  of  Ghent, 
made  the  sensational  assertion  that  Mueller  had  been  misled 
by  a  too  vivid  imagination,  and  that  in  the  mutual  relations  of 
insects  and  flowers  the  bright  colors  of  the  floral  leaves  have 
not  the  important  role  that  he  had  attributed  to  them.  All 
the  flowers  in  nature  might  be  as  green  as  their  leaves,  without 
their  pollination  being  compromised.  It  is  not  their  sense  of 
color  but  their  sense  of  smell  which  enables  insects  to  discover 
flowers  which  contain  nectar  and  pollen. 

Assertions  so  revolutionary  were  naturally  received  with 
much  incredulity,  and  in  some  instances,  as  Plateau  naively 
remarks,  were  criticised  with  merciless  severity.  While  reply- 
ing to  his  critics  with  admirable  courtesy.  Plateau  constantly 
sought  for  new  evidence,   and  actively  maintained  his  views 

212 


IS  CONSPICUOUSNESS  AN  ADVANTAGE? 

to  the  close  of  a  long  life.  Had  he  been  content  to  refute 
Mueller's  theory  that  insects  exhibit  color  preferences,  it  is 
probable  that  he  would  have  met  with  little  opposition;  but 
his  sweeping  denial  of  the  value  of  conspicuousness  in  any 
degree  to  flowers  has  not  met  with  general  acceptance  and 
can  be  easily  shown  to  be  incorrect. 

If  the  flowers  of  the  common  pear  {Pyrus  communis)  be  de- 
prived of  their  petals,  honey-bees  will  at  once  cease  to  visit 
them  for  nectar,  as  is  shown  by  the  following  observations.  A 
cluster  of  seven  blossoms  near  the  end  of  a  branch  was  watched 
for  fifteen  minutes  and  received  eight  visits  from  honey-bees. 
The  petals  were  now  all  removed  and  it  was  observed  for  a 
second  quarter  of  an  hour.  Though  a  number  of  bees  flew 
near  by,  it  received  not  a  single  visit.  During  a  third  fifteen 
minutes  there  were  two  visits,  due  in  part  to  association,  for 
the  bees  came  from  other  blossoms  on  the  same  tree,  which  had 
proved  the  first  source  of  attraction. 

Two  other  clusters  of  flowers,  growing  side  by  side,  but  nearer 
the  bole  of  the  tree,  consisting  each  of  8  flowers,  were  observed 
for  fifteen  minutes,  and  16  visits  of  honey-bees  were  noted.  The 
petals  of  one  of  these  clusters  were  now  removed.  During 
fifteen  minutes  the  adjacent  cluster,  which  still  retained  its 
petals,  received  11  visits,  while  not  one  was  made  to  the  cluster 
without  petals.  In  one  instance  a  bee  hovered  over  it  but  did 
not  alight.  These  results  were  very  conclusive,  and  showed 
that  the  bees  were  guided  almost  entirely  by  the  presence  of 
the  petals. 

Similar  results  were  obtained  from  an  experiment  with  two 
groups  of  flowers  belonging  to  the  common  borage  {Borago 
officinalis,  Fig.  103.)  They  were  distant  apart  about  6 
inches;  one  contained  5  flowers;  the  other,  which  was  at  a  little 
higher  elevation,  contained  4  flowers.     They  were  both  watched 

213 


THE  FLOWER  AND  THE  BEE 

for  ten  minutes.  The  first  received  15  visits  from  honey-bees, 
the  second  13  visits.  The  blue  corollas,  together  with  the  cone 
of  black  anthers,  were  now  removed  from  the  flowers  of  the 
first  group.  The  two  groups  were  now  observed  for  a  second 
ten  minutes;  the  first  received  no  visits,  the  second  7  visits 
from  honey-bees.  Once  a  bee  hovered  around  the  denuded 
flowers  of  the  first  group,  but  failed  to  alight,  although  they 
contained  an  abundance  of  nectar.  There  were  scattered 
upon  the  ground  many  partially  withered  corollas  and  it  was 
interesting  to  notice  that  a  bee  was  twice  seen  to  fly  down 
toward  them.  The  value  of  conspicuousness  was  here  again 
very  clearly  established. 

A  staminate  flower  of  the  garden-squash  {Cucurbita  maxima) 
was  placed  under  observation  for  ten  minutes  and  received  12 
visits,  8  from  honey-bees  and  4  from  bumblebees  {Bombus 
terricola).  The  yellow  corolla  was  then  removed,  and  it  was 
watched  for  a  second  ten  minutes,  during  which  it  received  only 
a  single  visit  from  a  bumblebee.  Two  squash-flowers,  both 
staminate,  growing  side  by  side,  their  corollas  touching,  were 
then  selected.  Both  were  observed  for  ten  minutes.  Number 
one  received  6  visits — 4  from  bumblebees,  2  from  honey-bees; 
while  number  two  received  13  visits,  all  from  bumblebees. 
The  fresher  condition  of  the  second  flower  probably  accounted 
for  the  larger  number  of  visits.  The  yellow  corolla  was  now 
cut  away  from  number  two,  and  both  flowers  were  watched  for 
another  ten  minutes.  No  visits  were  made  to  the  denuded 
flower,  but  number  one  received  12  visits,  6  from  honey-bees, 
and  6  from  bumblebees.  In  the  previous  experiments  the 
number  of  visits  to  the  complete  flowers  were  numerous  and 
decisive.  On  the  contrary,  they  ceased  almost  entirely  to  the 
decorollated  flowers,  although  they  contained  an  ample  supply 
of  nectar.     That  the  white,  blue,  and  yellow  corollas  were  bene- 

214 


Fig.  103.     Borage.     B  or  ago  officinalis 
When  the  petals  were  removed  honey-bees  at  once  ceased  to  visit  the  flowers 


THE   FLOWER   AND   THE   BEE 

ficial  to  the  flowers  of  their  respective  species  does  not  admit  of 
any  question. 

Since  there  are  a  few  green  flowers,  which  secrete  nectar  freely 
and  are  frequently  visited  by  insects  despite  the  absence  of 
bright  colors,  as  the  garden-asparagus,  basswood  and  wood- 
bine, Plateau  argued  that,  therefore,  all  flowers  might  be  as 
green  as  their  leaves  without  diminishing  the  number  of  insect 
visits.  But  a  careful  examination  of  greenish  flowers  shows 
that  for  the  most  part  they  are  small  and  wind-pollinated  or 
self-fertilized  and  are  never,  or  only  rarely,  visited  by  insects. 
In  the  case  of  the  exceptions,  which  contain  an  abundance 
of  nectar,  they  will  be  often  visited  after  the  nectar  has  once 
been  found,  but  it  will  not  be  found  as  quickly  as  it  would  be  if 
they  were  conspicuous.  When  honey-bees  are  given  the  choice 
between  a  conspicuous  and  an  inconspicuous  object,  both  sup- 
plied with  honey,  they  will  discover  first  and  visit  more  fre- 
quently the  conspicuous  object,  as  can  be  easily  shown  by  the 
following  experiment: 

About  25  bees  were  accustomed  to  visit  a  piece  of  dull-gray 
board  on  which  a  small  quantity  of  sugar-syrup  had  been 
placed.  Three  feet  away  from  the  board  there  was  laid  on 
the  grass  of  the  lawn  a  dried  yellow  everlasting-flower  (Heli- 
chrysum  hradeatum)  containing  a  small  quantity  of  honey. 
On  the  opposite  side  of  the  board,  3  feet  away,  there  was  placed 
a  green  apple-leaf,  on  which  there  was  also  a  small  quantity 
of  honey.  As  soon  as  the  sugar -syrup  of  the  board  had  been 
wholly  consumed  the  bees  began  describing  circles  in  the  air  in 
a  search  for  a  further  supply.  They  repeatedly  found  the 
yellow  flower  and  at  one  time  there  were  3  bees  sucking  honey 
on  it;  but  not  a  single  bee  found  the  honey  on  the  apple-leaf. 
According  to  the  reiterated  statement  of  Plateau  all  flowers 
might  be  as  green  as  their  leaves  without  their  pollination  be- 

216 


IS  CONSPICUOUSNESS  AN   ADVANTAGE? 

ing  compromised,  and  color  and  form  are  of  little  consequence 
in  comparison  with  odor.  But  this  experiment  and  many 
others  showed  that  color  contrast  was  of  great  value— in  this 
particular  experiment  it  was  indispensable.  If  the  leaves  pro- 
vided with  an  ample  supply  of  honey  could  not  obtain  a 
single  visit,  how  little  chance  would  there  be  for  an  isolated 
plant  with  small  green  flowers  growing  in  a  secluded  location 
attracting  visitors !  But  a  bright-colored  flower  in  the  same 
locahty  would  be  much  more  likely  to  gain  the  attention  of 
poUinators. 

From  the  preceding  experiments  it  appears  that  as  soon  as 
a  conspicuous  flower  loses  its  petals  bees  cease  to  visit  it,  and 
that  they  find  a  bright-colored  flower  more  quickly  than  they 
do  a  green  one.  It  remains  to  show  that  they  can  distinguish 
between  different  colors,  for,  if  they  cannot,  then,  a  poly- 
chromatic flora  possesses  no  advantage  over  one  in  which  the 
flowers  are  all  of  the  same  hue.  For  this  purpose  we  have 
made  use  of  differently  colored  flowers  of  the  same  species, 
which  are  ahke  in  form  and  odor,  and  differ  only  in  color. 
Differently  colored  slips  of  paper  might  also  be  employed. 

A  honey-bee  was  trained  to  visit  a  purple  sweet  pea,  on  the 
wings  of  which  honey  had  been  placed.  The  flower  was  laid 
on  a  dull-colored  board,  raised  several  feet  above  the  ground. 
After  the  bee  had  become  accustomed  to  the  purple  color,  while 
it  was  absent  at  the  hive,  the  purple  flower  was  moved  1^2  inches 
to  the  right  and  a  red  sweet  pea  with  honey  on  the  wings  was 
put  in  its  place.  The  bee  returned  to  the  purple  flower  and 
after  taking  up  a  load  of  honey  left  again  for  the  hive. 

During  its  absence  no  change  was  made  in  the  position  of 
the  flowers.  The  bee  on  its  return  hovered  over  the  red  sweet 
pea  and  alighted  on  it  for  a  moment  or  two,  but  then  left  for 
the  purple  flower  where  it  took  up  its  load  of  honey. 

217 


THE  FLOWER  AND  THE  BEE 

^Vhile  the  bee  was  away  the  flowers  were  transposed,  the 
red  blossom  being  put  in  the  place  of  the  purple,  and  the 
purple  in  the  place  of  the  red.  The  bee  returned  to  the  purple 
flower. 

After  the  bee  had  left  for  the  hive  the  flowers  were  again 
transposed.  On  its  return  the  bee  manifested  a  little  hesita- 
tion, but  soon  went  to  the  purple  blossom. 

While  the  bee  was  absent,  the  flowers  were  still  again 
transposed,  but  on  its  return  it  flew  directly  to  the  purple 
flower. 

Although  the  experiment  was  continued  further,  it  is  not 
necessary  to  give  additional  details,  since  it  is  clear  that  the 
honey-bee  was  able  to  distinguish  the  purple  sweet  pea  from 
the  red  one.  In  the  same  way  a  honey-bee  showed  that  it  was 
able  to  distinguish  between  the  red  and  yellow  flowers  of  Portu- 
laca  grandiflora;  and  the  greenish  white  and  purple  flowers  of 
Cobwa  scandens. 

In  another  experiment  blue  and  red  slips  of  paper  3  inches 
long  by  1  inch  wide  were  used  instead  of  flowers.  After  the 
bee  had  made  a  few  visits  to  the  blue  paper,  on  which  there  was 
a  small  quantity  of  honey,  the  red  slip  of  paper  with  a  little 
honey  on  it  was  placed  6  inches  to  the  right  of  it.  The  bee 
returned  to  the  blue  paper,  which  still  remained  in  its  original 
position.  The  blue  and  red  papers  were  now  transposed  9 
times  and  in  each  instance  the  bee  returned  to  the  blue  paper, 
from  which  it  gathered  its  load  of  honey.  In  another  experi- 
ment a  honey-bee  distinguished  with  equal  ease  between  blue 
and  yellow  slips  of  paper.  Bee-keepers  have  long  recognized  the 
ability  of  bees  to  distinguish  between  different  colors,  and  at 
times  paint  their  hives  red,  white,  and  blue  in  order  to  prevent 
young  queens  from  entering  the  wrong  hive  after  mating. 

If  bees  can  so  easily  distinguish  between  different  colors,  how, 

218 


IS  CONSPICUOUSNESS  AN   ADVANTAGE? 

then,  does  it  happen  that  they  so  often  visit  indiscriminately 
in  our  gardens  the  differently  colored  varieties  of  the  same 
species  of  flower,  as  the  white,  yellow,  orange,  red,  and  purple 
varieties  of  Zinnia,  or  the  red,  white,  blue,  and  purple  varieties 
of  bachelor's-button  {Centaurea  cyanus)  ?  It  is  obvious  that 
the  flowers  belonging  to  each  species  are  alike  in  shape,  odor, 
and  nectar,  and  differ  in  hue  alone.  Under  these  circumstances 
it  is  for  the  advantage  of  bees  to  pass  freely  from  one  color  to 
another,  and  this  they  speedily  learn  to  do. 

Since  bees  are  able  to  distinguish  between  different  colors, 
and  cease  to  visit  flowers  as  soon  as  the  brightly  colored  floral 
leaves  are  removed,  and  find  a  flower  which  contrasts  sharply 
in  color  with  green  foliage  more  quickly  than  one  which  is  simi- 
larly colored,  conspicuousness  is  clearly  a  great  advantage  in 
attracting  insects. 

If,  however,  brightly  colored  flowers,  as  in  the  case  of  many 
gaudy  exotics  of  cultivation,  are  nectarless  and  yield  little  or 
no  pollen,  bees  soon  learn  that  no  food  is  to  be  obtained  from 
such  blossoms,  and  remembering  this,  thereafter  visit  them 
only  occasionally.  The  large  flowers  of  the  cultivated  purple 
clematis  {Clematis  Jackmanni),  for  example,  are  nectarless  and 
odorless,  but  produce  a  small  amount  of  pollen.  Careful  and 
almost  continuous  observation  showed  that  they  were  at  times 
visited  by  honey-bees  and  solitary  bees,  which  gathered  all  of 
the  pollen.  I  inspected  the  flowers  many  times  without  find- 
ing any  insects,  and  a  casual  observer  might  easily  conclude 
that  they  were  entirely  neglected.  After  the  pollen  had  been 
removed  there  was  no  reason  why  insects  should  continue  their 
visits. 

For  the  purpose  of  learning  whether  the  visits  of  bees  could 
not  be  induced  in  large  numbers,  I  next  placed  on  a  few  of  the 
flowers  sugar-syrup,  which  is  an  odorless  sweet  liquid.     Honey- 

219 


THE   FLOWER  AND   THE   BEE 

bees  soon  began  to  visit  the  flowers,  and  continued  to  come  in 
increasing  numbers  so  long  as  I  supplied  the  syrup.  This  ex- 
periment was  repeated  with  many  other  garden-flowers  which 
were  nectarless  with  similar  results.  Wild  and  field  flowers 
also  which  in  one  locality  freely  secrete  nectar,  as  alfalfa,  white 
clover,  buckwheat,  and  goldenrod,  and  are  visited  by  many 
insects,  are  sometimes  in  other  localities  nectarless  and  almost 
entirely  neglected.  Insects,  therefore,  perceive  the  colors  and 
forms  of  neglected  flowers,  and  the  rarity  of  their  visits  is  the 
result  of  their  memory  of  the  absence  of  food  materials.* 

*  Readers  desiring  to  pursue  this  subject  further  are  referred  to  the  follow- 
ing articles  by  the  author:  "Is  Conspicuousness  an  Advantage  to  Flowers?" 
Amer.  Nat,  vol.  43,  pp.  338-349,  1909.  "Can  Bees  Distinguish  Colors.'" 
Amer.  Nat,  vol.  44,  pp.  673-692,  1910.  "The  Pollination  of  Green  Flowers," 
Amer.  Nat.,  vol.  46,  pp.  83-107,  1912.  "Conspicuous  Flowers  Rarely  Visited 
by  Insects,"  Jour.  Animal  Behavior,  vol.  4,  pp.  147-175,  1914.  "The  Evolu- 
tion of  Flowers,"  Scientific  Monthly,  vol.  4,  pp.  110-119,  1917. 


220 


CHAPTER  XIV 
THE   COLORS  OF  NORTH   x\MERICAN  FLOWERS 

THE  distribution  of  coloration  in  our  flora  is  a  question 
of  much  interest,  but  one  which  up  to  the  present  time 
had  received  very  httle  attention.  Some  years  ago  I 
began  an  inquiry  as  to  how  many  flowers  there  are  of  each  color 
in  the  flora  of  North  America.  In  northeastern  America,  north 
of  Temiessee  and  east  of  the  Rocky  Mountains,  there  have  been 
described  4,020  species  of  flowering  plants,  or  Angiosperms. 
Partly  by  direct  examination  and  partly  by  reference  to  various 
systematic  works,  I  have  tabulated  the  entire  number  according 
to  the  predominant  colors  of  their  flowers.  I  find  that  in  the 
area  named  there  are  1,244  green,  956  white,  801  yellow,  260 
red,  434  purple,  and  325  blue  flowers.  In  every  hundred  species 
there  are  30.9  green,  23.8  white,  19.9  yellow,  6.4  red,  10.9  pur- 
ple, and  8  blue  flowers.  Their  distribution  among  the  different 
flower  series  is  shown  in  the  following  table: 


Series 

Green 

White 

Yellow 

Red 

Purple 

Blue 

Total 

Monocotyledons 

Dicotyledons — 
Choripetalae: 

Apetaltc 

Polypetahe 

Gamopetahie 

Total 

857 

175 
140 

70 

82 

89 
410 
375 

41 

51 
333 
37G 

22 

45 

84 
lOG 

22 

24 
193 
198 

34 

57 
234 

1,058 

384 
1,217 
1,361 

1,244 

956 

801 

257 

437 

325 

4,020 

The  green,  white,  and  yellow  flowers  number  3,001,  or  three- 
fourths  of  the  entire  number;    while  the  red,  purple,  and  blue 

'221 


THE   FLOWER  AND   THE   BEE 

amount  to  only  1,019.  Although  there  are  many  exceptions, 
especially  in  the  pulse,  mint,  and  figwort  families,  the  first 
group  contains  largely  regular,  rotate,  or  tubular  flowers  with 
the  nectar  accessible  to  a  large  miscellaneous  company  of  in- 
sects, as  beetles,  flies,  butterflies,  wasps,  and  bees.  Yellow  ir- 
regular or  bilabiate  flowers  seem  to  be  often  the  result  of  the 
greater  persistence  of  the  primitive  yellow  pigment,  and  its 
little  tendency  to  vary  with  the  specialization  of  the  corolla. 
Many  white  irregular  flowers  are  undoubtedly  due  to  rever- 
sion. The  flowers  belonging  to  the  second  group  are  very 
frequently  irregular  or  bilaterally  symmetrical,  with  the  nec- 
tar concealed,  and  are  chiefly  attractive  to  long-tongued  bees, 
butterflies,  and  flies.  The  tendency  of  flowers  to  change  from 
green,  white,  and  yellow  to  red,  purple,  and  blue,  is  much 
stronger  than  the  reverse;  but  red,  purple,  and  blue  flowers 
usually  have  the  petals  white  or  yellowish  at  the  base  and  in 
the  bud,  and  not  infrequently  the  whole  corolla  reverts  to  one 
of  these  colors. 

Have  these  relations  any  significance.^  Undoubtedly  they 
have.  They  are  signals  pointing  out  to  us  the  course  our  flora 
has  pursued  in  its  evolution.  The  green,  white,  and  yellow 
colors  are  older  and  more  primitive  than  the  red,  purple,  and 
blue,  and  were  much  more  common  in  the  primordial  flora. 
The  red,  purple,  and  blue  flowers  are,  as  a  whole,  of  much  more 
recent  origin,  and  have  been  developed  from  green,  white,  and 
yellow  blossoms.  For  example,  the  buttercups  are  a  much  older 
genus  than  the  columbines  or  larkspurs,  and  the  cinquefoils 
are  more  ancient  than  the  pea,  bean,  or  vetch;  while  again  the 
viburnums  are  older  than  the  honeysuckles.  The  orchids 
have  certainly  developed  more  recently  than  the  lilies.  Occa- 
sionally irregular  flowers  revert  to  their  ancestral  stages  and 
produce   perfectly    regular   forms.     These   color   changes   are 

222 


COLORS  OF  NORTH  AMERICAN   FLOWERS 

often  recapitulated  by  individual  flowers;  white  corollas  chang- 
ing to  red,  as  in  the  sweet-william,  or  to  yellow,  as  in  the  climb- 
ing honeysuckle,  or  from  yellow  to  red,  as  in  lantana  and  the 
flowering  currant  {Ribes  aureum),  or  from  red  to  blue,  as  in  the 
forget-me-not  {Myosotis  versicolor). 

Let  us  next  inquire  how  many  of  these  4,020  flowers  founds 
in  northeastern  America  are  pollinated  by  the  wind  ami^how 
many  by  insects.  Among  the  wind-pollinated  plants  are  the 
grasses,  sedges,  and  rushes;  many  homely  weeds  like  the  pig- 
weeds, sorrels,  nettles,  and  ragweeds,  as  well  as  many  decidu- 
ous-leaved bushes  and  trees,  as  the  alders,  poplars,  elms, 
beeches,  and  birches.  After  a  careful  examination  of  every 
genus  I  place  the  number  of  wind-pollinated  plants  (including 
a  few  pollinated  by  water)  at  about  1,046.  This  number  is, 
perhaps,  a  little  too  large,  for  in  the  case  of  some  Western 
species  there  are  no  recorded  observations  a,nd  they  may  be 
self-pollinated.  Still  it  cannot  be  far  from  correct,  since  the 
grasses  and  sedges  alone  in  this  area  include  705  species,  the 
rushes  47,  the  pondweeds  (including  8  water-flowers)  42,  the 
deciduous-leaved  trees  and  shrubs  71,  the  chenopods  and  ama- 
ranths 54,  and  36  species  in  the  CompositoB. 

Wind-pollinated  plants  have  usually  small  and  inconspicu- 
ous flowers  which  are  green  or  dull-colored,  and  which  flower 
and  fruit  entirely  unnoticed.  It  would  be  of  no  advantage  to 
them  to  produce  bright  colors  or  sweet  odors,  for  the  wind 
bloweth  where  it  listeth  regardless  of  all  such  attractions.  The 
birches,  however,  have  golden  and  greenish-yellow  aments,  and 
the  blossoms  of  the  elm  are  purplish.  The  glumes  of  grasses 
and  the  perianths  of  rushes  are  also  often  purplish  or  reddish. 
So  conspicuous  are  the  flowers  of  some  rushes  that  they  attract 
a  few  insects.  The  sorrels  may  have  the  entire  plant  red- 
colored,  and  butterflies  may  seek  nectar  in  the  flowers.     The 

223 


THE   FLOWER  AND   THE   BEE 

plantains  are  midway  between  wind-pollination  and  insect- 
pollination,  and  some  species  display  several  hues  and  are 
pleasantly  scented.  But  as  a  whole  wind-pollinated  plants 
have  small,  greenish  flowers. 

Setting  aside  the  great  company  of  dull-colored,  wind-polli- 
nated flowers,  there  remain  in  northeastern  America  2,972 
species  which  are  pollinated  by  insects  or  are  self-pollinated. 
Of  this  number  223  have  green,  955  white,  790  yellow,  257 
red,  422  purple,  and  325  blue  flowers. 

Green  Flowers 

The  primitive  color  of  flowers  was  doubtless  green.  If  the 
theory  of  the  poet  Goethe  that  the  flower  is  a  metamorphosed 
bud,  or  part  of  a  branch  of  leaves,  be  admitted,  this  is  self- 
evident.  Despite  many  attacks,  this  doctrine  has  never  been 
disproven,  at  least  historically.  In  most  flowers  the  calyx  has 
remained  green,  and  in  some  genera,  as  Hepatica,  its  deriva- 
tion from  leaves  is  evident  from  inspection.  It  is  not  uncom- 
mon in  the  buttercups,  anemones,  poppies,  mustards,  tuhps, 
and  many  other  genera  for  both  the  sepals  and  petals  to  re- 
vert to  green  leaves,  and  I  have  before  me  a  flower  of  Fuchsia 
with  three  white  petals,  while  the  fourth  is  a  green  leaf.  In 
Cactus  no  line  of  demarcation  can  be  drawn  between  bracts, 
sepals,  and  petals,  and  all  three  are  in  the  same  spiral  series. 
Even  assuming  that  foliage-leaves  were  derived  from  sterile 
spore-bearing  organs  (sporophylls),  there  is  every  reason  to  be- 
lieve that  the  sheathing  bracts  of  the  earliest  flowers  were 
green.  In  the  Black  Hills  a  fossil  "flower"  of  a  cycad-like 
plant  (Cycadeoidea)  has  been  found  by  Wieland,  which  is  pro- 
tected by  an  indefinite  number  of  hairy,  green,  bract-like 
leaves.     (Fig.  104.) 

The  green  hue  of  both  green  leaves  and  flowers  is  produced 

224 


Fig.  104.     Diagram  of  the  "Flower,"  or  Strobilus,  of  Cycadeoidea  dacotensis, 
a  Fossil  Plant  from  the  Black  Hills,  South  Dakota 

a.  Hairy,  green  sheathing  bracts;  b,  folded  stamens;  c,  elongated  axis;  d,  conical  mass  of 
sterile  and  fertile  scales,  the  latter  bearing  terminal  naked  seeds.  From  somewhat 
similar  ancestors  modern  flowers  were  perhaps  derived.     (After  Wieland) 


THE  FLOWER  AND  THE   BEE 

by  a  pigment  called  chlorophyll,  or  leaf-green.  If  a  few  leaves 
of  grass,  or  of  any  common  plant,  be  placed  in  alcohol  the 
chlorophyll  will  dissolve  out,  forming  a  yellowish-green  solution, 
and  the  leaves  will  be  left  entirely  white.  Chemical  examina- 
tion shows  that  there  are  two  kinds  of  chlorophyll  in  the  solu- 
tion, a  blue-green,  which  is  abundant,  and  a  yellow-green  pig- 
ment which  is  less  common.  Place  this  solution  in  bright 
sunlight  and  the  green  color  will  soon  be  destroyed.  Green 
seaweeds,  when  left  on  the  beach  by  the  waves,  soon  turn 
yellowish  owing  to  the  destruction  of  the  chlorophyll.  In  liv- 
ing leaves  and  green  flowers  under  the  action  of  bright  light  the 
green  pigment  is  constantly  being  destroyed  and  renewed,  so 
that  no  two  leaves  are  identical  in  hue,  and  no  leaf  long  remains 
the  same  shade.  Four  hundred  years  ago  a  German  poet, 
Freidank,  observed  this  fact. 

"Many  hundred  flowers 
Alike  none  ever  grew; 
Mark  it  well,  no  leaf  of  green 
Is  just  another's  hue." 

Leaf -green,  or  chlorophyll,  is  not  only  the  most  common,  but 
it  is  also  the  most  useful  of  all  pigments,  for  all  life  depends 
upon  it  for  existence.  Leaves  containing  this  pigment  are 
able  to  make  use  of  the  energy  of  the  sunbeam,  and  to  manu- 
facture out  of  water  and  the  carbonic  dioxid  in  the  air,  starch, 
one  of  the  principal  plant-foods.  That  is,  out  of  mineral  sub- 
stances they  build  up  an  organic  substance.  As  all  animals 
are  dependent  either  directly  or  indirectly  on  vegetation  for 
support,  the  destruction  of  chlorophyfl  would  mean  the  dis- 
appearance of  life  from  the  earth.  AU  hving  beings  are  de- 
pendent upon  chlorophyfl  and  the  radiant  energy  of  the  sun. 
"In  this  sense,"  says  Tyndall,  "we  are  afl  souls  of  fire  and 

226 


COLORS  OF  NORTH  AMERICAN  FLOWERS 

children  of  the  sun."  In  the  making  of  starch  the  leaf -factories 
absorb  most  of  the  red,  orange,  and  blue  rays  of  light,  but  make 
no  use  of  the  green,  and  hence  the  color  of  foliage  is  green,  a 
most  fortunate  result,  since  a  landscape  of  any  other  hue  would 
have  been  almost  intolerable. 

Most  of  the  223  insect-pollinated  or  self-pollinated  green 
flowers  in  northeastern  America  are  small  or  even  minute,  as 
in  the  pinweeds  (Lechea).  Many  have  no  petals  and  their 
color  is  due  to  the  green  calyx,  as  15  species  of  the  buck- 
wheat family,  8  species  of  sandworts  and  chickweeds,  several 
species  of  the  rose  family,  the  rock -maple  (Fig.  105),  and  the 
water-purslane.  Many  green  flowers  show  undoubted  evidences 
of  retrogression,  as  numerous  spurges,  the  water -milfoils  where 
the  sepals  and  often  the  petals  have  been  lost;  while  the 
composite  flowers  of  the  wormwoods  {Artemisia)  and  ragweeds 
(Ambrosia)  have  retrograded  until  they  have  become  wind- 
polHnated. 

The  flowers  of  the  vine  family  depend  chiefly  upon  their 
fragrance  to  attract  insects.  The  green  petals  never  expand 
but  fall  away  by  separating  at  the  base  and  coiling  spirally 
upward.  The  fragrance  which  resembles  that  of  mignonette 
can  be  perceived  at  a  long  distance.  Kerner  relates  that  in  a 
journey  up  the  Danube  he  found  the  whole  valley  of  the  Wachan 
so  filled  with  the  scent  of  vine-flowers  that  it  seemed  impossible 
that  they  could  be  far  off,  yet  the  nearest  vines  were  300  yards 
from  the  boat. 

While,  in  general,  green  flowers  are  visited  chiefly  by  flies, 
beetles,  and  the  smaller  bees,  as  Clintonia  horealis,  the  large 
yellowish-green  panicles  of  the  false  hellebore  (Veratrum  viride), 
and  the  smaller  clusters  of  the  smilax  family,  there  are  a  few 
species  which  secrete  nectar  very  abundantly  and  are  visited 
by  great  numbers  of  insects.     Basswood  is  one  of  the  most 

2!27 


THE  FLOWER   AND  THE  BEE 

valuable  honey-plants  in  North  America,  and  its  greenish 
flowers  yield  annually  thousands  of  pounds  of  a  rich,  aromatic 
honey.  The  rock-maple  in  early  spring,  and  the  Boston  ivy  and 
woodbine  (Fig.  106)  later  in  the  season,  are  also  valuable  sources 
of  nectar  to  the  bee-keeper.  Large  green  flowers  occur  in 
various  exotic  species  of  the  nightshade  family  and  in  some 
Brazilian  orchids.  They  are  strongly  scented  in  the  evening 
and  are  attractive  to  nocturnal  moths. 

Green  flowers  often  contain  other  pigments  besides  chloro- 
phyll, or  leaf-green,  as  carrotin,  tinging  them  various  shades  of 
yellow,  or  green  granules  may  be  mingled  with  violet-colored 
sap  as  in  the  dull-purple  corolla  of  belladonna  (Atropa  bella- 
donna), while  the  brownish  color  of  the  gooseberry  is  due  to  red- 
cell  sap  and  chlorophyll. 

Yellow  Flowers 

The  green  pigment,  or  chlorophyll,  in  leaves  is  invariably 
accompanied  by  two  yellow  pigments,  carrotin,  so-called  be- 
cause it  is  common  in  the  root  of  the  carrot,  and  xanthophyll,  or 
leaf-yellow.  Carrotin,  to  which  most  yellow  flowers  owe  their 
hue,  is  a  solid  substance,  occurring  in  petals  in  small  round 
granules  called  plastids.  It  is  very  widely  distributed  in  sea- 
weeds, fungi,  lichens,  mosses,  ferns,  and  the  higher  plants,  in 
autumn  leaves  and  in  fruits  and  seeds.  It  is  insoluble  in  water, 
but  readily  soluble  in  ether.  The  yellow  plastids  of  flowers  are 
not  always  round,  but  are  sometimes  angular  as  in  the  garden- 
nasturtium.  In  the  tomato,  asparagus,  thorn-bush,  and  in 
some  species  of  rose,  the  plastids  of  the  fruit  are  spindle-formed, 
or  irregular -shaped,  and  are  fire-red,  orange-red,  or  yeHowish 
red.  In  yellow  leaves  the  plastids  are  round ;  but  in  autunmal 
leaves  they  occur  in  irregular  masses. 

The  scarlet  poppy,  tulip,  and  fire-red  canna  owe  their  colors 

228 


Fig.  105.     Yellowish-green  Flowers  of  Rock-Maple.     Acer  saccharum 


THE  FLOWER  AND  THE  BEE 

to  a  mixture  of  yellow  plastids  and  red  cell-sap.  On  the  other 
hand,  dingy  or  dull  colors  result  from  a  combination  of  violet 
sap  with  yellow  granules.  Carrotin  is  much  less  sensitive  to  the 
effects  of  light  than  chlorophyll,  as  may  be  readily  shown  by 
the  following  experiment:  If  the  carrotin  contained  in  a  few 
slices  of  carrot-root  be  dissolved  out  in  ether,  the  yellow  solu- 
tion will  not  lose  its  color  under  ten  days,  while  the  green 
hue  of  a  solution  of  chlorophyll  will  disappear  in  twenty-four 
hours. 

Yellow  was  doubtless  one  of  the  first  colors  displayed  by  the 
flowers  of  the  primitive  flora;  and,  in  view  of  the  wide  distribu- 
tion of  yellow  pigments  in  leaves,  the  development  of  yellow 
petals  offers  little  difficulty,  and  many  leaves,  fruits,  and 
flowers  afford  suggestions  as  to  the  way  in  which  this  change 
might  take  place.  The  quantity  of  yellow  pigment  in  the 
foliage  of  different  plants  varies  greatly;  while  in  some  species 
it  is  scarcely  perceptible,  in  others  it  is  so  abundant  as  to  tinge 
the  whole  plant  yellow,  and  in  a  few  golden-yellow  species  the 
chlorophyll  appears  to  be  nearly  or  wholly  excluded.  Many 
fruits  change  from  green  to  yellow  in  ripening,  and  yellow  color- 
ing is  especially  prominent  in  foliage  both  in  spring  and  autumn. 
Not  infrequently  the  change  from  green  to  yellow  occurs  in 
flowers  after  they  have  opened,  as  in  penny -cress  (Thlaspi) 
and  bitter  cress  (Cardamine) ;  in  the  yellow  water-lily  {NymphcBa 
advena)  the  outer  sepals  are  half  green  and  half  yellow;  while 
yellow  tulips  in  expanding  display  every  shade  from  dark  green 
to  bright  yellow.  In  double  English  buttercups  in  the  bud  the 
petals  are  wholly  green,  becoming  later  golden  yellow.  Every 
stage  of  the  transition  from  green  to  yellow  is  constantly  illus- 
trated by  fruits  and  flowers. 

According  to  Stahl  it  is  more  costly  and  difficult  to  produce 
chlorophyll,  which  requires  for  its  formation  the  presence  of 

230 


\ 


COLORS  OF  NORTH  AMERICAN   FLOWERS 

nitrogen,  phosphorus,  potassium,  magnesium,  and  iron,  than 
carrotin,  which  is  composed  of  only  carbon  and  hydrogen. 
Anything,  therefore,  which  retards  or  prevents  the  formation 


^ 

^^#^'"^ 

Mi  i 

Fig.  lOG.     Woodbine.     Psedera  qitinquejolia 
Small  green  flowers 


of  chlorophyll,  as  the  absence  of  the  proper  elements,  will  cause 
the  flower  to  become  yellowish;  and,  as  has  been  shown,  carrotin 
is  much  more  persistent  in  intense  sunlight  than  the  green 
pigments.  In  the  beginning  of  entomophily  (adaptation  to 
insects)  there  would  naturally  be  from  time  to  time  more  or 

231 


THE  FLOWER  AND  THE  BEE 

less  yellow  flowers  in  the  ancient  flora,  and  the  advantage 
afforded  by  greater  conspicuousness  would  soon  cause  them  to 
become  common. 

Among  the  flowers  which  owe  their  yellow  color  chiefly  to 
carrotin  are  the  Abutilon,  Adonis,  squash,  Forsythia,  sunflower, 
jewelweed  {Impatiens  hiflora),  Kerria  japonica,  evening-prim- 
rose, yellow  roses,  dandelion,  and  nasturtium.  The  yellow  pig- 
ment xanthophyll  does  not  occur  in  plastids,  but  is  dissolved 
in  the  cell -sap.  To  it  are  due  the  yellow  color  of  the  peel  of  the 
lemon,  the  yellow  flowers  of  the  dahlia,  butter-and-eggs  {Linaria 
vulgaris),  snapdragon,  and  all  the  yellow-flowering  thistles  as 
well  as  many  other  flowers.     (Fig.  107.) 

There  are  790  yellow  flowers  in  northeastern  America,  which 
vary  in  size  from  the  large  campanulate  cups  of  the  squash  to 
the  small  flowers  of  the  creeping  buttercup.  Usually  they  are 
wheel-shaped,  as  in  the  buttercups  and  fivefingers;  but  not 
infrequently  they  are  very  irregular  in  form,  as  in  the  pea  and 
figwort  families,  where  the  corolla  bears  a  more  or  less  fancied 
resemblance  to  a  butterfly  or  the  head  of  a  reptile.  As  a 
whole,  however,  they  are  much  less  specialized  than  red  and 
blue  flowers.  Irregular  yellow  flowers  probably  owe  their  hue 
largely  to  the  great  persistency  of  the  yellow  pigment  carrotin. 
Both  yellow  and  white  flowers  ?re  common  in  primitive  families. 
For  instance,  in  the  buttercup  family  there  are  38  yellow  and 
26  white  flowers;  in  the  mustard  family,  46  yeflow  and  54  white; 
in  the  rose  family,  39  yellow  and  35  white. 

While  trees  and  shrubs  with  white  flowers  abound  every- 
where, trees  and  shrubs  with  yellow  flowers  are  comparatively 
rare.  A  number  of  common  trees  have  small  yellowish  or 
greenish -yellow  flowers,  as  the  rock-maple,  striped  maple,  chest- 
nut, and  basswood;  while  among  shrubs  there  are  the  barberry, 
fly-honeysuckle,   jessamine,    and   bush-honeysuckle.     Familiar 

232 


Fig.  107.     Cucumber.     Cucumis  sativus 
The  yellow  flowers  owe  their  color  to  plastids  of  carotin  in  the  cells 


THE  FLOWER  AND  THE  BEE 

yellow- flowered  shrubs  under  cultivation  are  the  Forsythia, 
golden  currant,  and  yellow  rose.  The  yellow  hue  of  the  wil- 
lows is  due  to  their  anthers,  for  they  have  no  perianths. 
Most  plants  with  yellow  flowers  are  herbaceous.  Wlien  the 
blossoms  are  of  small  size  they  are  usually  assembled,  like  small 
white  flowers,  in  clusters,  as  in  the  mustard,  saxifrage,  carrot, 
and  thistle  families.     (Fig.  108.) 

In  the  pink  family,  although  there  are  5Q  white  flowers,  there 
are  no  indigenous  yeUow  species;  and  in  the  aquatic  water- 
plantain  family  the  entire  19  species  are  white;  but,  on  the 
other  hand,  in  the  St.-John's-wort  family  there  are  22  yellow  and 
2  red  flowers,  while  white  fails  entirely.  Yellow  is  very  com- 
mon among  the  primroses  and  nightshades,  but  rare  among  the 
heaths  and  gentians.  Irregular,  or  zygomorphic,  yellow  flowers 
are  much  rarer  than  regular  forms,  and  are  most  common  in 
the  orchis,  pea,  violet,  figwort,  and  honeysuckle  families,  which 
contain  a  total  of  104  species. 

In  the  aster  or  thistle  family  {Coiii'positoe)  there  are  262  yel- 
low flowers  and  134  white.  Though  this  is  the  highest  of  plant 
families,  the  central  florets  of  each  head  are  very  small,  and 
the  corolla  has  been  very  little  modified;  consequently  the 
primitive  yellow  has  been  largely  retained.  Some  large  genera, 
as  golden  aster  {Chrysopsis)  and  goldenrod  {Solidago)  with  one 
exception,  and  groundsel,  or  Senecio,  have  all  the  flowers  of  this 
hue.  So  abundant  are  many  yellow-flowered  species  in  various 
localities,  as  the  sunflowers,  goldenrods.  Coreopsis,  Spanish 
needles  {Bidens  aristosa),  gum-plant  {Grindelia),  crownbeard 
{Verhesina),  marigolds,  and  dandelions  that  yellow  is  more 
predominant  in  the  floral  landscape  of  North  America  than  any 
other  color.  Yellow  might  well  be  our  national  color,  and  the 
goldenrod  our  national  flower.  It  is  the  most  bright  and  cheer- 
ful of  colors  since  it  reflects  the  largest  amount  of  light,  and  it  is 

234 


Fig.  108.     Garden- Marigold.     Calendula  officinalis 

The  most  familiar  yellow  flower  of  cultivation 


THE  FLOWER  AND  THE  BEE 

doubtless  for  this  reason  that  yellow  flowers  enjoy  so  great 
popularity  both  in  the  United  States  and  Europe. 

The  goldenrods,  a  genus  of  beautiful  and  stately  plants, 
which  are  everywhere  common  in  North  America,  bloom  from 
midsummer  until  late  fall.  They  are  most  valuable  as  a  source 
of  honey,  and  in  New  England  are  the  main  reliance  of  the  bee- 
keeper for  winter  stores  for  his  colonies.  They  are  great  favor- 
ites with  the  honey-bee,  and  are  visited  also  by  more  than  100 
other  species  of  insects.  The  bright-yellow  color  of  the  flowers 
renders  them  conspicuous  both  by  day  and  evening;  and  as 
the  temperature  of  the  inflorescence  at  night  is  several  degrees 
above  that  of  the  surrounding  air,  they  sometimes  serve  as  a 
nocturnal  refuge  for  insects. 

"And  ill  the  evening,  everywhere. 
Along  the  roadside,  up  and  down, 
I  see  the  golden  torches  flare. 

Like  lighted  street-lamps  in  the  town. 

I  think  the  butterfly  and  bee. 

From  distant  meadows  coming  back, 

Are  quite  contented  when  they  see 

These  lamps  along  the  homeward  track." 

— Sherman. 

Yellow  flowers  in  their  natural  state  exhibit  but  httle  varia- 
tion in  color.  They  change  most  readfly  to  white,  and  less 
often  to  red  and  blue.  Under  cultivation  Darwin  noted  a  double 
yellow  hollyhock,  which  suddenly  turned  one  year  into  a  single 
white  form,  and  a  chrysanthemum  has  been  observed  to  bear 
both  yellow  and  white  flowers.  Some  species  of  mustard  reg- 
ularly fade  to  white,  and  not  a  few  white  flowers  show  that 
they  are  derived  from  an  ancestral  yellow  by  retaining  vestiges 
of  this  color  at  the  base  of  the  petals,  as  the  water-crowfoot. 
The  pale-yellow  flowers  of  CEnothera  laciniata,  of  the  golden 


COLORS  OF  NORTH  AMERICAN   FLOWERS 

currant  {Rihes  aureum),  and  of  the  bush-honeysuckle  {Diervilla 
trifida)  in  fading  change  to  rose  or  red.  A  species  of  forget-me- 
not  {Myosotis  versicolor)  is  at  first  yellow,  changing  later  to  sky- 
blue.  In  the  violet  family  the  smallest  and  simplest  species  is 
yellow,  and  the  most  highly  specialized  is  blue,  while  all  the 
intermediate  stages  are  shown  by  the  pansy. 

White  Flowers 

White  flowers,  of  which  there  are  955  species  in  northeastern 
North  America,  are  most  common  in  our  flora  as  well  as  in  that 
of  Europe.  They  contain  no  pigments,  although  in  some  in- 
stances they  contain  a  white  substance,  which,  when  chemically 
treated,  yields  a  yellow  hue.  Like  the  snow  and  powdered 
glass,  they  owe  their  color  to  their  optical  properties — that  is, 
to  the  reflection  and  refraction  of  the  rays  of  light  by  the  minute 
cells  of  which  they  are  composed.  They  are  derived  from  green, 
yellow,  red,  and  blue-colored  ancestors,  and  are  the  result  of 
retrogression.  In  this  connection  the  studies  of  white  leaves 
by  Rodrique,  Laurent,  and  Timpe,  which  clearly  show  evidences 
of  degeneration,  are  of  much  interest.  Such  leaves  are  thinner 
than  normal  green  leaves,  and  consist  wholly  of  cellular  tissue, 
the  palisade-cells  being  absent.  Whatever  impairs  the  vigor 
or  vitahty  of  the  plant,  as  cold,  impoverished  soil,  injury  to  the 
roots,  or  continued  self-fertilization,  will  cause  the  floral  hues 
to  become  paler,  or  change  to  white.  I  once  transplanted  a 
scarlet  poppy  when  in  bud,  and  the  flowers  became  much  smaller 
and  changed  to  pure  white.  White  flowers  are  most  common 
in  the  cold  days  of  early  spring,  and  gradually  become  rarer 
toward  autumn.  In  the  arctic  climate  of  Spitz bergen  the 
flowers  are  chiefly  white,  and  there  are  few  yellow  and  red, 
while  blue  appears  to  fail  entirely.  In  east  Greenland  the 
flowers  are  likewise  chiefly  white,  and  among  26  species  there 

237 


THE   FLOWER  AND   THE   BEE 

is  only  1  blue.  It  has  been  observed  that  garden-balsams  be- 
come white  when  ammonia  is  withheld  from  the  soil,  but  re- 
gain their  color  when  it  is  supplied.  Asa  Gray  is  reported  to 
have  said  that  any  colored  flower  might  revert  to  white,  and 
this  is  undoubtedly  true. 

On  the  other  hand,  whatever  stimulates  the  growth  of  a 
plant,  as  bright  sunlight,  strong  manures,  or  crossing,  increases 
the  brilliancy  of  the  flowers.  When  lowland  white  flowers 
have  been  cultivated  in  the  intense  light  of  Alpine  summits 
they  have  in  some  cases  become  red.  An  application  of  nitrate 
of  soda  win  increase  the  brifliancy  of  a  flower;  and  tulips,  when 
treated  with  a  strong  manure,  flush  and  lose  their  variegated 
colors.  The  brightness  of  floral  hues  is  also  increased  by  cross- 
ing. The  presence  of  pigments  in  the  flowers  is  often  correlated 
with  its  presence  or  absence  in  the  leaves  and  stems;  and  it  is 
often  possible  from  an  examination  of  the  vegetative  organs  to 
determine  beforehand  whether  the  flowers  will  be  white  or  not. 
The  white-flowered  variety  of  Portulaca  has  green  stems,  while 
the  yellow  and  red  varieties  have  red  stems.  A  variety  of 
Cyclamen  with  crimson  flowers  has  the  leaves  purplish  beneath, 
while  the  leaves  of  the  white-flowered  variety  are  paler  and 
green  on  the  under-side.  The  red  maple  has  the  flowers,  twigs, 
and  young  leaves  all  crimson,  while  the  entire  plant  of  the  wood- 
sorrel,  including  the  flowers  and  fruit,  is  frequently  red.  In 
Sedum  purpureum  the  petals  are  purple,  and  sometimes  the  en- 
tire plant;  and  in  the  stonecrop  {Sedum  acre)  the  foliage  is 
yellowish  green  and  the  flowers  bright  yellow.  It  is  evident 
that  in  many  species  the  color  of  the  flowers  is  determined  by 
the  pigment  content  of  the  plant  as  a  whole. 

It  is  easy  to  understand  why  white  flowers  are  the  most 
common  in  nature,  and  why  they  are  truest  to  name  under 
cultivation.     Naturally   florists   find   that   they   can   develop 

238 


COLORS   OF  NORTH   AMERICAN   FLOWERS 

any  desired  color  variety  from  a  white  flower  more  easily  than 
from  one  already  containing  pigments. 

Nature  is  an  excellent  economist.  Trees  and  shrubs  whose 
fruits  are  edible  by  man  or  birds  usually  produce  their  blossoms 
in  boundless  profusion,  and  they  are  almost  invariably  white, 
or  nearly  so — the  two  most  noteworthy  exceptions  being  the 
peach  and  huckleberry,  which  have  red  or  reddish  flowers. 
Among  trees  are  the  apple,  pear,  plum,  cherries  in  variety,  the 
quince  and  the  orange ;  while  among  shrubs  are  the  blackberries, 
blueberries,  raspberries,  hollies,  cornels,  and  thorn-bushes. 
There  is  nothing  more  beautiful  in  the  floral  vegetation  of  this 
world  than  an  apple-orchard  laden  with  expanding  blossoms. 
The  great  masses  of  flowers  form  billowing  banks  of  whiteness, 
tinged  with  rose  and  flecked  wuth  the  vivid  green  of  the  un- 
folding leaf -buds,  from  which  exliales  the  well-known  sweet 
fragrance  of  the  apple-blossom. 

"Spring  walks  abroad  in  all  the  fields  to-day; 

Her  touch  has  left  the  apple  orchards  white; 
The  baby  buds  that  waited  for  the  May 

Have  shaken  out  their  petals  overnight; 
Against  the  rugged  boughs  they  softly  press. 

Weaving  in  the  mantle  of  their  loveliness. 

Spring  walks  abroad  with  songs  of  life  and  cheer; 

A  thousand  gifts  she  joyfully  bestows; 
But  all  her  fairest  handiwork  is  here 

Where  orchards  toss  their  drifts  of  scented  snows." 

Alfred  Russel  Wallace,  who  spent  many  years  of  his  life  in 
exploring  the  vast  forests  of  the  Amazon  and  the  islands  of  the 
Malay  Archipelago,  declares:  "I  have  never  seen  anything 
more  glorious  than  an  old  crab-tree  in  full  blossom;  and  the 
horse-chestnut,  lilac,  and  laburnum  will  vie  with  the  choicest 
tropical  trees  and  shrubs."     (Fig.  109.) 

239 


Fig.  109.     Button-Bush.     Cephalanthus  occidentalis 
A  handsome  swamp-shrub  with  small  white  flowers  in  dense  spherical  heads 


Con 


Fig.  110.     Carrot.     Dauciis  Carota 

spicuousness  is  gained  by  the  aggregation  of  many  small  white  flowers  in  a  level-topped 
flower-cluster.  In  the  lower  figure  the  "bird-nest"  formed  by  the  cluster  after  it  has 
gone  to  seed  is  shown 


THE   FLOWER  AND   THE   BEE 

The  largest  tree-flowers  known  belong  to  the  Magnolia. 
One  Southern  species  has  a  white  flower,  with  a  purple  centre, 
which  measures  ten  inches  across.  "Their  effect  in  early  spring 
is  grand  beyond  description,  illuminating  the  whole  landscape 
and  filling  the  air  with  rich  perfume."  Of  the  five  northern 
species  four  are  white,  and  one  is  greenish  yellow.  Magnificent 
white  flowers  are  likewise  displayed  by  several  species  of  pond- 
lilies;  but  very  frequently  white  flowers  are  of  small  size,  and 
conspicuousness  is  gained  by  their  aggregation  in  masses. 

Small,  densely  clustered  white  flowers  standing  in  the  same 
horizontal  plane  and  affording  a  convenient  landing-place  for 
insects  are  very  common  in  the  mustard,  saxifrage,  carrot, 
honeysuckle,  and  aster  families.  This  type  of  flower-cluster 
is  excellently  illustrated  by  the  carrot  family,  or  Umbelliferoe. 
(Fig.  110.)  To  this  family  belong  the  caraway  and  carrot,  the 
wild  parsnip,  the  water-hemlock,  and  the  water -parsley,  plants 
growing  luxuriantly  by  the  roadside,  along  the  river,  and  in  the 
meadow.  The  flowers  differ  very  little  in  structure,  and  the 
species  can  be  separated  only  by  the  aid  of  the  mature  fruit. 
Insects  of  every  kind  are  welcome,  and  no  other  family  of 
flowers  has  so  large  a  number  and  variety  of  visitors.  The 
nectar  is  fully  exposed,  and  self-fertilization  is  prevented  by 
the  anthers  and  stigmas  maturing  at  different  times.  In  the 
CompositcB  126  species  have  either  the  ray  or  disk  florets  white. 
(Fig.  111.)  In  bicolored  heads,  or  capitula,  where  the  rays  are 
white  and  the  disk  flowers  yellow,  tJiere  can  be  no  doubt  that 
the  white  rays  are  derived  from  yellow-colored  ancestors.  In 
crownbeard  (Verbesina)  all  of  the  5  species  have  yellow  disks, 
but  1  has  white  and  4  yellow  rays.  In  the  genera  everlasting 
(Antennaria)  and  cudweed  {Gnaphalium)  the  yellowish -white 
flowers  have  retrograded  and  lost  their  original  yellow  hue. 

In  the  orchis,  pea,  mint,  and  figwort  families  there  occur 

242 


Fig.  111.  Mayweed.     Anthemis  Cohila 
Yellow  centre  with  white  rays,  showing  the  advantage  of  white  in  rendering  the  flowers 


conspicuous 


THE  FLOWER  AND   THE  BEE 

many  irregular  white  flowers,  which  have  been  derived  from 
yellow,  red,  and  blue  forms,  partly  as  the  result  of  retrogression, 
and  partly  because  of  the  advantage  arising  from  a  contrast  of 
colors  between  closely  allied  species  blooming  at  the  same  time. 
There  is  a  white  variety  of  the  scarlet  runner,  and  the  bright- 
blue  larkspur  is  sometimes  white.  Both  white  and  pink  flowers 
have  been  seen  on  a  single  plant  of  the  snapdragon,  and  a 
pure-white  form  of  the  bright-red  Polygala  is  sometimes  found, 
and  also  of  the  violet-blue  pickerel-weed.  Everywhere  there 
is  ample  evidence  that  a  flower  containing  pigments  may  easily 
change  to  white. 

Finally  there  are  many  small  white  flowers  which  are  soli- 
tary, or  at  least  not  densely  clustered.  Some  5Q  such  species 
belong  to  the  pink  family;  they  are  low-tufted,  weak  herbs  of 
a  spreading  or  ascending  habit  represented  by  the  chickweeds 
and  sandworts.  They  are  visited  chiefly  by  flies  and  the  smaller 
bees. 

Individual  white  flowers  may  develop  bright  coloration  dur- 
ing their  period  of  blooming.  The  white  sepals  of  the  Christ- 
mas rose  {Helleborus  niger)  regularly  change  to  green;  the 
flowers  of  a  species  of  lantana  are  at  first  white,  but  later  be- 
come yellow;  while  the  corolla  of  the  sweet-william,  common 
pink,  and  Hibiscus  mutabilis  turn  from  white  to  red.  In  the 
bellflower  (Campanula)  the  flowers  remain  white  until  they  ex- 
pand, when  they  change  to  blue.  Thus  under  suitable  condi- 
tions there  may  come  from  white  flowers  a  great  variety  of 
colored  ones.  But,  as  has  been  already  pointed  out,  white 
flowers  are  most  common  in  primitive  families  in  which  yellow 
flowers  are  also  very  abundant. 


244 


COLORS  OF  NORTH  AMERICAN  FLOWERS 


Red  Flowers 

There  are  only  257  flowers  in  the  northeastern  flora  which 
are  described  as  red;  but  as  there  are  also  109  red-purple 
flowers,  which  should  be  classed  with  them,  red  flowers  are  thus 
not  so  rare  as  would  at  first  appear.  While  green  and  yellow 
flowers  for  the  most  part  contain  solid-colored  granules  or 
plastids,  red  and  blue  flowers  owe  their  coloration  to  a  group  of 
pigments  dissolved  in  the  cell-sap  and  called  collectively  antho- 
cyanin.  Considerable  evidence  has  been  obtained  that  the 
anthocyanins  are  derived  from  the  yellow  pigments  of  plants. 
^Vhen  the  anthocyanin  salts  are  acid  the  flowers  are  red,  when 
neutral  violet,  and  when  alkaline  blue;  but  when  the  acid  salt 
is  neutralized  the  flowers  in  some  instances  become  colorless. 
The  color  may  be  again  restored  by  an  acid. 

Anthocyanin  is  very  widely  distributed  among  plants,  espe- 
cially among  the  higher  or  flowering  plants.  In  early  spring  the 
new  leaves  of  many  species  are  suffused  with  it,  as  the  red 
maple,  the  blueberry,  and  rhubarb;  and  in  autumn  it  imparts 
vivid  scarlet  and  crimson  hues  to  the  maples,  huckleberries, 
sumacs,  and  blackberries.  It  is  often  abundant  on  the  under- 
side of  floating  aquatic  leaves  and  radical  leaves  growing  in 
rosettes,  along  stems,  and  in  the  root  of  the  beet.  It  is  the 
prevalent  color  of  the  Coleus  and  purple  beech,  and  it  adorns 
many  fruits  and  berries  when  ripe.  The  anthocyanin  of  foliage 
is  usually  red,  since  the  cell-sap  of  the  vegetative  organs  is,  as  a 
rule,  acid. 

As  the  result  of  many  experiments  Overton  found  that  the 
formation  of  red  coloration  in  plants  was  influenced  by  three 
factors,  a  cell-sap  rich  in  sugar,  intense  light,  and  low  tempera- 
ture. When  cut  stems  of  Lilium  Martagon  and  other  land- 
plants  were  placed  in   a  2-per-cent  invert   sugar-solution,  red 

245 


THE   FLOWER  AND   THE   BEE 

anthocyanin  soon  appeared  in  the  upper  side  of  the  leaves,  while 
leaves  of  plants  in  control  experiments  j^laced  in  pure  water 
remained  green.  Water-plants,  like  Hydrocharis,  placed  in  a 
sugar -solution  also  developed  red  coloring  in  the  leaves  in  a 
few  days.  When  Overton  removed  his  plant-cultures  to  the 
shade,  the  red  coloring  quickly  disappeared,  but  again  re- 
turned when  they  were  exposed  to  bright  light.  Leaves, 
flowers,  and  fruits  frequently  display  red  coloring  on  the  side 
exposed  to  direct  sunlight,  while  the  side  in  the  shade  remains 
green.  During  the  summer  the  leaves  of  plants  in  the  Alps 
are  much  oftener  red-colored  than  in  the  lowlands,  because  the 
night  temperature  is  lower  and  the  light-intensity  higher.  Ker- 
ner  found  that  the  anthocyanin  in  plants  grown  in  an  Alpine 
garden  at  an  elevation  of  2,195  metres  above  the  level  of  the 
sea  was  brighter-colored  and  more  abundant  than  in  the  botani- 
cal garden  at  Vienna.  The  glumes  of  grasses,  the  leaves  of 
stonecrops,  and  the  pure-white  petals  of  some  flowers  became 
red  or  purplish  red.  Winter  leaves  become  red-colored  be- 
cause a  lower  temperature  causes  the  sugar  content  to  be  in- 
creased at  the  cost  of  the  starch. 

While  some  ecologists  regard  anthocyanin  as  merely  a  by- 
product of  the  chemical  activities  of  the  cell,  others,  as  Stahl, 
think  that  its  role  is  the  absorption  of  heat.  When  leaves  con- 
taining anthocyanin  were  placed  in  a  vessel  of  water  the  tem- 
perature of  the  water  was  raised  4  degrees  higher  than  that  of 
an  equal  quantity  of  water  containing  green  leaves  of  the  same 
superficial  area,  both  vessels  being  placed  in  the  sunlight.  It 
is  readily  conceivable  that  in  early  spring,  when  the  temperature 
of  the  air  is  near  the  freezing-point,  this  additional  heat  might 
be  a  great  advantage.  Red  coloring  is  seldom  common  in 
foliage  containing  much  yellow  pigment,  consequently  antho- 
cyanin is  rare  in  the  birches,  which  have  yellow  leaves  in  spring 

246 


COLORS  OF  NORTH   AMERICAN   FLOWERS 

and  fall,  but  abundant  in  the  same  seasons  in  the  red  maple, 
which  contains  much  less  carrotin. 

The  anthocyanins  are  glucosides,  and  there  are  many  differ- 
ent kinds,  which  are  named  after  the  flowers  from  which  they 
are  extracted,  as  that  from  the  geranium  {Pelargonium)  is  called 
pelargonidin,  that  from  the  larkspur  {Delphinium)  delphinidin, 
and  that  from  Malva  malvidin.  The  colors  of  flowers  depend 
upon  whether  there  is  a  small  or  large  quantity  of  these  pig- 
ments present,  or  a  mixture  of  more  than  one,  and  also  on  the 
presence  of  yellow  pigments. 

Red  has  more  motor  power  in  stimulating  the  eye  than  other 
colors,  and  is  consequently  used  commonly  for  railroad  and 
other  forms  of  signalling.  It  is  the  favorite  color  of  savage 
races,  and  it  renders  persons  living  constantly  in  rooms  painted 
bright-red  nervous  and  excitable.  Since  it  will  excite  the  bull 
to  fury  and  enrage  the  turkey-gobbler,  it  is  not  surprising  to 
find  that  flowers  pollinated  by  humming-birds  and  sunbirds 
are  usually  crimson  or  scarlet.  (Fig.  112.)  There  are  also 
many  red  pinks,  lilies,  and  orchids,  which  are  pollinated  by 
red-colored  butterflies,  a  fact  which  led  Mueller  to  believe  that 
they  were  likewise  influenced  by  red  coloration. 

The  distribution  of  red  flowers  shows  that  in  the  sequence 
of  floral  colors  they  are  more  primitive  than  blue,  for  they 
occur  in  more  primitive  genera  and  families  in  some  of  which 
blue  flowers  are  unknown.  The  buckwheat  family  contains 
11,  the  pink  family  22,  the  rose  family  19,  the  mallow  family 
13,  the  evening -primrose  family  10,  the  heath  family  10,  and 
the  huckleberry  family  11  red-flowered  species;  but  in  north- 
eastern America  there  are  no  blue  flowers  in  any  of  these 
families.  The  flowers  in  the  above  famihes  are  regular  in  form 
and  but  little  modified,  so  that  it  is  probable  that  red  flowers 
were  abundant  long  before  blue.     The  prevalence  of  red  color- 

247 


THE  FLOWER  AND   THE  BEE 

ing  in  primitive  groups  of  flowers  to  the  exclusion  of  blue  is 
due  to  the  strongly  acid  condition  of  the  cell-sap.  But  in  the 
lily,  pea,  gentian,  phlox,  and  mint  families,  which  have  highly 
specialized  and  often  irregular  flowers,  both  red  and  blue 
flowers  are  common.  This  second  group  of  families  are  ad- 
mittedly among  the  most  recently  developed  in  our  flora,  and 
therefore  we  conclude  that  blue  flowers  are  of  later  origin  than 
red  and  in  many  instances  are  derived  from  them. 

Trees  with  red  flowers  are  rare,  but  shrubs  are  common. 
Of  trees,  the  peach,  red  buckeye,  and  red  maple  (Fig.  113)  are 
the  best-known  examples.  Many  red-flow^ered  shrubs  occur 
in  the  rose,  heath,  and  huckleberry  families.  The  handsomest 
American  shrubs  are  undoubtedly  the  Rhododendrons,  Kalmias, 
and  Azaleas,  which  exhibit  a  great  variety  of  rose,  pink,  flame- 
colored  and  red  shades.  It  is  rather  remarkable  that  among 
571  species  of  Composiiw  there  are  only  9  red  flowers.  On  the 
other  hand,  13  species,  or  one-half  the  mallow  family,  have 
pink  or  red  blossoms;  and  there  are  22  species  in  the  pink 
family.  In  the  buckwheat  family  the  petals  are  wanting,  but 
the  sepals  are  often  red  and  sometimes  the  seed-vessels,  stems, 
and  leaves.  In  the  poppy  family  the  flowers  are  crimson, 
scarlet,  or  red,  and  the  sap  is  also  yellow  and  red.  The  most 
brilliant  red  flower  in  our  flora  is  the  cardinal-flower  {Lobelia 
cardinalis.  Fig.  112),  which  is  pollinated  by  humming-birds. 
There  are  also  three  flowers  which  are  scarlet  outside,  but 
yellow  within,  and  rarely  all  over;  they  are  the  wild  columbine, 
trumpet-honeysuckle,  and  Maryland  pinkroot,  to  all  three  of 
which  humming-birds  are  common  visitors. 

Blue  Flowers 
There  are  325  blue  flowers  and  194  blue-purple  flowers  in 
the  flora  of  northeastern  America.     Blue  is  the  highest  color 

248 


Fig.  112.     Cardinal-Flower.     Lohelia  cardinalis 
The  most  brilliant  red  flower  in  our  flora.     A  humming-bird  flower 


THE  FLOWER  AND  THE  BEE 

in  the  floral  world,  and  undoubtedly  blue  flowers,  as  a  whole, 
were  the  latest  evolved.  They  adorn  the  culminations  in  flower- 
building.  Simple,  small,  regular  flowers,  as  has  already  been 
shown,  are  usually  white  or  yellow,  as  the  water-plantains, 
buttercups,  and  fivefingers,  while  many  red  flowers  are  also 
primitive  in  structure.  But  corollas  which  are  two-lipped,  or 
bilaterally  symmetrical,  and  highly  modified  are  most  frequently 
blue  or  blue-purple  and  are  often  variegated  with  other  hues. 
For  instance,  in  the  buttercup  family,  while  the  buttercups  are 
yellow,  the  bilateral  larkspurs  and  monk's-hoods  have  blue 
sepals  and  petals.  Again,  in  the  rose  family  the  regular  rotate 
fivefingers  are  yellow  and  the  roses  are  white  or  red,  and  blue 
flowers  are  entirely  absent;  but  in  the  "sister  family"  of  the 
pea  family  (Papilionacecp),  where  the  corolla  is  butterfly- 
shaped,  blue  and  blue-purple  forms  prevail,  which  are  polli- 
nated by  bees.     (Figs.  20,  36,  and  37.) 

In  blue  flowers  the  cell-sap  is  neutral  or  alkaline,  and  the 
anthocyanin  salts  are  violet-colored  or  various  shades  of  blue 
and  purple.  There  may  be  only  a  single  pigment  or  a  mixture 
of  pigments.  The  color  change  from  red  to  blue  may  be  arti- 
ficially illustrated  by  dipping  a  red  rose  in  an  alkaline  solution, 
when  it  becomes  blue,  but  the  red  hue  is  again  restored  by  an 
acid.  Many  individual  flowers  illustrate  this  color  transition. 
The  flowers  of  the  common  borage  (Borago  officinalis)  are  at 
first  red,  but  later  turn  blue,  as  do  those  of  the  lungwort 
iPulmonaria) ;  the  corolla  of  the  stickseed  is  red  before  ex- 
panding, but  afterward  becomes  bright  blue,  and  the  pale-pink 
blossoms  of  the  forget-me-not  also  soon  change  to  blue.  The 
gradual  transition  from  an  acid  cell -sap  to  an  alkaline  one  is 
shown  by  fruits,  which  are  at  first  sour  and  red,  but  with  ma- 
turity become  sweet  and  blue  or  purple.  The  reverse  change 
of  color  may  also  take  place,  and  in  a  variety  of  perennial  phlox 

250 


Fig.  113.     Red  Maple.     Acer  riihrum 

Pistillate  flowers.     The  entire  flower  is  crimson,  also  the  bud  scales,  twigs,  and  the  foliage 
both  in  spring  and  autumn 


THE  FLOWER  AND   THE   BEE 

the  flowers  were  a  deep  blue  in  the  morning,  changing  to  beauti- 
ful deep  rose  by  evening. 

In  many  species  of  plants  the  cell-sap  is  so  nearly  neutral 
that  both  red  and  blue  flowers  may  be  produced,  or  both  hues 
may  appear  in  the  same  flower.  Darwin  has  described  a  hya- 
cinth which  bore  on  the  same  truss  a  perfectly  pink  and  a  per- 
fectly blue  flower,  another  truss  which  w^as  blue  on  one  side  and 
red  on  the  other,  and  also  flowers  which  were  striped  longi- 
tudinally with  red  and  blue.  According  to  Hildebrand,  red 
and  blue  cells  may  occur  side  by  side  in  the  same  petal,  and  in 
the  sweet  violet  {Viola  odoraia)  there  is  a  layer  of  blue  cells  in 
the  epidermis,  under  which  there  is  a  layer  of  red  cells  in  the 
mesophyll. 

Blue  anthocyanin  is  seldom  found  in  yellow  flowers,  and  plants 
in  which  the  sap  is  very  strongly  acid,  as  the  roses,  may  never 
produce  blue  flowers.  De  Candolle,  therefore,  concluded  that 
yellow,  red,  and  blue  flowers  could  not  occur  in  the  same  species; 
but  this  doctrine,  to  use  the  words  of  Lindley,  "must  now  be 
laid  up  in  the  limbo  of  pleasant  dreams."  This  supposed  law 
is  contradicted  by  the  hyacinth,  pansy,  and  larkspur  {Delphi- 
nium cardinale). 

Among  the  Monocotyledons  of  northeastern  America  (the 
series  containing  the  grasses,  sedges,  lilies,  and  orchids)  there 
are  only  3-t  blue  flowers,  found  chiefly  in  the  lily  and  iris  famiHes. 
It  might  be  supposed  that  the  wonderful  orchis  family,  where 
the  flowers  run  riot  in  their  strange,  bizarre  forms,  would  con- 
tain many  blue  flowers;  but  such  is  not  the  fact,  and  out  of 
6,000  species  in  the  world  there  is  only  one,  Vanda  coerulea  of 
India,  which  is  blue. 

Turning  to  the  Dicotyledons,  there  are  no  blue  flowers  among 
the  apetalous  species.  This  rarity  continues  among  the  poly- 
petalous  families,  for  blue  flowers  are  absent  in  the  poppy, 

252 


COLORS  OF   NORTH   AMERICAN  FLOWERS 

mustard,  saxifrage,  currant,  rose,  geranium,  oxalis,  spurge, 
holly,  balsam,  vine,  mallow,  St.-John's-wort,  rock-rose,  cactus, 
evening-primrose,  ginseng,  cornel  families,  and  with  three  ex- 
ceptions in  the  UmbelliferoB.  But  in  three  genera  of  the  butter- 
cup family,  the  columbines,  larkspurs,  and  monk's-hoods,  the 
violet  family,  and  the  pea  family  {PapilionaceoB)  they  are  com- 
mon. All  these  flowers  are  highly  specialized,  irregular,  and 
pollinated  by  bees. 

In  the  more  primitive  families  of  the  Gamopetaloe,  the  series 
with  the  petals  united  into  a  corolla-tube,  as  the  heath,  prim- 
rose, olive,  honeysuckle,  and  madder  families,  blue  flowers  are 
again  absent.  They  belong  chiefly  to  the  gentian,  phlox,  water- 
leaf,  borage,  verbena,  mint,  and  figwort  families;  while  a 
second  maximum  is  reached  in  the  bellflower  family  {Cam- 
panulaceoo)  and  the  Composifw.  All  of  these  families  are  of 
comparatively  recent  origin,  and  they  contain  nearly  400  blue 
and  blue-purple  flowers.  In  the  mint  and  figwort  families, 
flowers  of  these  colors  are  very  numerous,  and  are  often  dotted, 
striped,  or  maculated  with  white,  yellow,  and  red.  They  pre- 
sent the  culmination  of  color  display  among  flowering  plants. 
They  are  mostly  bee-flowers,  and  the  majority  of  bee-flowers 
everywhere  are  red  or  blue.  Of  100  species  of  bee-flowers  in 
the  Alps,  34  are  white  or  yellow,  and  G6  red  or  blue.  In  the 
German  and  Swiss  flora,  15'-2  bee-flowers  are  white  and  yellow, 
and  330  red,  violet,  or  blue.  Genera  adapted  to  bees  often 
display  a  variety  of  colors,  as  violet,  blue,  brown,  red,  yellow, 
and  white,  especially  when  they  bloom  in  the  same  locality  at 
the  same  time,  this  contrast  in  hue  enabling  the  bees  to  remain 
more  easily  constant  to  one  species.  Common  examples  are 
the  aconites,  sages,  and  clovers. 

These  highly  specialized  flowers  often  possess  intricate  floral 
mechanisms  and  very  peculiar  forms,  as  the  skullcap,  monkey- 

253 


THE   FLOWER   AND   THE   BEE 

flower,  snapdragon,  and  monk's-hood,  while  the  nectar  is  so 
carefully  concealed  that  few  insects  besides  the  long-tongued 
bees  can  obtain  it.  While  in  general  all  blue  flowers  are  bee- 
flowers,  not  all  bee-flowers  have  bilabiate  or  irregular  forms. 
The  gentian  family  contains  many  perfectly  regular  blue  flowers 
which  are  adapted  to  bees.  The  gentians  are  very  abundant 
in  the  Alps,  and  display  great  masses  of  vivid  blue  coloring. 
Huxley,  while  seeking  health  in  the  bracing  air  of  these  moun- 
tains, found  great  pleasure  in  studying  these  flowers,  to  an 
account  of  which  his  last  paper  was  devoted.  The  intensity  of 
their  blue  coloration  has  been  well  described  by  Bryant  in 
his  lines  to  a  fringed  gentian  (Fig.  43) : 

"Blue,  blue,  as^  if  the  sky  let  fall 
A  flower  from  its  coerulean  wall." 

In  the  Campannlacece  there  are  2^2  blue  flowers  which  are 
bell-shaped;  while  in  the  Compositse  there  are  many  species 
in  Avhich  the  heads  have  blue  or  purple  rays,  as  in  the  autumnal 
flowering  asters.  A  preference  for  blue  coloring  shown  by  bees 
does  not  necessarily  imply  that  blue  affords  them  an  aesthetic 
pleasure;  but  only  that  they  recognize  the  signal  of  flowers 
adapted  to  their  visits. 

Purple  Flowers 
Red-purple  flowers  should  be  classed  with  red  flowers,  and 
blue-purple  flowers  with  blue  flowers  (Fig.  114);  but  in  addi- 
tion to  these  there  are  in  northeastern  America  134  dull  or 
lurid  purple  blossoms.  Many  of  them  are  brownish  or  green- 
ish purple,  of  small  size  and  rarely  visited  by  insects.  Green- 
ish-purple flowers  which  are  the  result  of  retrogression  occur 
in  the  milkweed  family  (Asclepiadaceoe)  and  Polygalacece. 
From  one  to  a  few  purplish  flowers  occur  in  a  great  number 

254 


Fig.  114.     Purple  Vervain.     Verbena  hastata 

In  parts  of  Iowa  in  favorable  seasons  the  landscape  is  fairly  blue  with  this  flower,  and  the 
bees  store  a  white  honey  from  it 


THE   FLOWER  AND   THE   BEE 


THE    COLORS  OF  NORTHERN   MONOCOTYLEDONOUS  FLOWERS 


Orders 

Families 

is 

^ 

1 

J 

0 

Paudanales  ■■•<,' 

{ 
Naiadales.  .  .  .  J 

Graminales .  .  .  / 
Arales / 

Xyridales 

Liliales 

Scitaminales .  .  . 
Orchidales.  •  •  •  / 

Typhacese 

Sparganiacese 

Naiadacese 

Scheuchzeriaceae..  . 

Alismaceae 

Vallisneriaceae 

Gramineae 

Cyperaceae 

Araceae 

1 

G 

1 

1 

7 
6 

2 

1 

3 

1 

2 

10 

19 
3 

2 
1 

1 

10 
13 
11 

3 
18 

1 

11 

1 

1 
8 

2 

1 

1 
14 

11 

2 

6 

14 
1 

2 

4 

42 

3 

371 

334 

5 

11 

5 

47 
5 
1 
5 

11 

11 

2 

4 

42 

4 

19 

3 

371 

334 

8 

11 

1 

6 

5 

1 

12 

4 

47 

24 

38 

23 

11 

1 

6 

1 

17 

1 

1 

61 

Lemnaceae 

Mayacaceae 

Xyridaceae 

Eriocaulaceae 

Bromeliaceae 

Commelinaceae .  .  .  . 
Pontederiaceaj .  .  .  . 

Juncaceae 

Melanthaceae 

Liliaceae 

Convallariaceae. .  .  . 

Smilaceae 

Haemodoraceae .  .  .  . 
Amaryllidaceae .... 

Dioscoreaceae 

Iridaceae 

Marantaceae 

Burmanniaceae .... 
Orchidaceae 

Total 

41 

82 

22 

22 

34 

857 

1058 

256 


COLORS  OF  NORTH  AMERICAN  FLOWERS 


of  families,  as  the  mustard  and  saxifrage  families.  The  pur- 
ple trillium  and  Dutchman's-pipe  have  brown  or  lurid-purple 
hues.  The  custard-apple  (Asinima  triloba)  is  at  first  greenish 
yellow,  changing  to  dull  purple.  In  most  instances  the  brown 
colors  of  flowers  are  due  to  a  mixture  of  chlorophyll  or  carrotin 
with  anthocyanin.  Among  the  brown  flowers  containing  two 
pigments  are  Carolina  allspice  {C ahjcanthus) ,  the  gooseberry, 
wild  ginger  {Asarum),  Adonis  vernalis,  and  various  orchids. 
The  black  spots  on  the  wings,  or  alse,  of  the  bean  {Vicia  Faba) 
contain  an  ohve-brown  pigment  dissolved  in  the  cell-sap. 
The  spots  appear  black  because  of  the  flat  epidermal  cells. 
(Fig.  101.) 

THE   COLORS  OF  NORTHERN  APETALOUS  FLOWERS 


Orders 

Families 

1 

IS 

1 

1 

3 
Oh 

H 

Piperales 

Juglandales 

Myricales.  .  •  .  / 

Salicales 

Fagales / 

Urticales ] 

I 
Santalales .  .  .  .  | 

Aristolochiales  .  . 
Polygonales 

Chenopodiales 

Saururaceae 

Juglandaceae 

Myricaceae 

Leitneriaceae 

Salicaceae 

13 
4 
1 

9 

7 

25 

3 

6 

8 

2 
2 

33 
38 
16 

8 

1 

2 

22 

1 
1 
1 
1 
4 
56 

32 
11 

5 
3 

2 

11 
1 

4 

5 

22 

4 

1 

10 

3 

3 
1 

2 

1 

13 

4 

1 

43 

18 

25 

7 

6 

8 

2 

5 

10 

74 

39 

17 

1 

8 

2 

12 

88 

Betulaceae .  .  . 

Fagaceae .... 

Ulmaceae 

Moraceae 

Urticaceae 

Loranthaceae 

Santalaceae 

Aristolochiaceae .  .  .  . 

Polygonaceae 

Chenopodiaceae 

Amaranthaceae .  ..... 

Phytolaccaceae 

Nyctaginaceae 

Aizoaceae 

Portulacaceae 

Caryophyllaceae .... 

Total . 

175 

89 

51 

45 

24 

384 

257 


THE   FLOWER   AND   THE   BEE 


THE  COLORS  OF  NORTHERN   POLYPETALOUS  FLOWERS 


Orders 


Families 


Ranales . 


Papaverales. . 
Sarraceniales. 


Resales . 


Geraniales. 


Nymphaeacese. .  . 
Ceratophyllaceae. 
Magnoliacese .  .  . 

Anonacese 

Ranunculaceae .  . 
Berberidacese .  .  . 
Menispermaceae . 
Calycanthacese. . 

Lauracese 

Papaveracese .  .  . 

Cruciferse 

Capparidacese. .  . 

Resedacese 

Sarraceniacese. .  . 

Droseracese 

Podostemacese .  . 
Crassulacese .  .  .  . 
Saxifragacese. .  .  . 
Grossulariaceae.  . 
Hamamelidacese. 

Platanacese 

Rosacese 

Pomaceae 

Drupaceae 

Mimosaceae 

Caesalpiniaceae .  . 
Krameriaceae .  .  . 
Papilionaceae .  .  . 

Geraniaceae 

Oxalidaceae 

Linaceae 

Zygophyllaceae .  . 

Rutaceae 

Simarubaceae .  .  . 
Polygalaceae .  .  .  . 
Euphorbiaceae. .  . 
Callitrichaceae. .  . 


0  26 

1  2 


5 

54 

3 

1 


30 
6 

1 

35 

27 

20 

3 

1 

39 

1 
1 


38 
3 


4 
10 
46 

2 
2 
1 


33 


24 


258 


COLORS  OF  NORTH  AMERICAN  FLOWERS 


THE  COLORS  OF  NORTHERN  POLYPETALOUS  FLOWERS 

{Cotttinned) 


Orders 


Sapindales. . 


Rhamnales 
Mai  vales.  . 


Parietales 


Opimtiales. .  . 
Thymeleales . 


Myrtales , 


Umbellales . 


Families 


Empetraceae .... 

Buxacese 

Limnanthaceae .  . 
Anacardiaceffi .  .  . 

Cyrillaceae 

Ilicacese 

Celastracese 

Staphyleacese .  .  . 

Aceraceae 

H  ippocastanacece 

Sapindacese 

Balsaminaceae. .  . 
Rhamnacese.  .  .  . 

Vitacese 

Tiliaceae 

Malvaceae 

Theaceae 

Hypericaceae. .  .  . 

Elatinaceae 

Cistaceae 

Violaceae 

Passifloraceae .  .  . 

Loasaceae 

Cactaceae 

Thymeleaceae .  .  . 
Elaeagnaceae .  .  .  . 

Lythraceae 

Melastomaceae .  . 

Onagraceae 

Trapaceae 

Haloragidaceae .  . 

Araliaceae 

Umbelliferae .  .  .  . 
Cornaceae 

Total 


140 


410 


333 


84 


193 


17 


57 


259 


THE  FLOWER  AND  THE   BEE 
THE  COLORS  OF  NORTHERN  GAMOPETALOUS  FLOWERS 


Orders 


Families 


Ericales . 


Primulales. .  .  . 
Ebenales 

Gentianales. .  . 


Polemoniales. 


Plantaginales .  . 
Rubiales 

Valerianales .  . 
Campanulales 


Clethraceae 

Pyrolacese 

Monotropacese .... 

Ericaceae 

Vacciniacese 

Diapensiacese 

Primulacese 

Plumbaginacese .  .  . 

Sapotacese 

Ebenacese 

Symplocacese 

Styracese 

Oleacese 

Loganiacese 

Gentianaceae 

Menyanthaceae. .  .  . 

Apocynacese 

Asclepiadacese .  .  .  . 
Convolvulaceae. .  .  . 

Cuscutacese 

Polemoniacese 

Hydrophyllacese. .  . 

Boraginacese 

Verbenacese 

Labiatae 

Solanacese 

Scrophulariacete. .  . 
Lentibulariacese .  .  . 
Orobanchacese .  .  .  . 

Bignoniaceae 

Martyniaceae 

Acanthaceae 

Phrymaceae 

Plantaginaceae .  .  . 

Rubiaceae 

Caprifoliaceae .... 

Adoxaceae 

Valerianaceae 

Dipsaceae 

Cucurbitaceae .  .  .  . 
Campanulaceae. .  . 

Cichoriaceae 

Ambrosiaceae .  .  .  . 
Compositae 

Total 

260 


15 
21 


72 


1 
22 
22 

5 

4 

8 


126    209 


375 


16 


59 


376 


106 


198 


234 


CHAPTER  XV 
BEES  AND   FRUIT-GROWING 

"All  the  forms  resemble,  yet  none  is  the  same  as  another; 
Thus  the  whole  of  the  throng  points  at  a  deep  hidden  law." 

— Goethe. 

WHILE  there  are  many  flowers  with  strangely  bizarre 
and  grotesque  shapes,  which  serve  as  hostelries  for 
bees  and  other  insects,  the  majority  of  blossoms  are 
perfectly  regular  in  form,  either  rotate  or  wheel-shaped,  cup- 
like or  tubular.  Such  are  the  buttercup,  fivefinger,  straw- 
berry, pear,  apple,  plum,  blackberry,  caraway,  carrot,  blue- 
berry, goldenrod,  daisy,  and  aster.  The  nectar  is  exposed  in 
many  species  to  every  passer-by,  and  attracts  a  great  horde  of 
miscellaneous  insects.  Go  into  an  orchard  of  Japanese  plums 
in  early  spring,  and  so  abundant  are  the  blossoms  that  they 
fairly  wreathe  the  limbs;  while  the  air  is  filled  with  a  cloud  of 
wild  bees  and  flies.  On  the  inflorescence  of  several  species  of 
the  carrot  family  {U mhelliferoB)  more  than  200  visitors  have 
been  coflected;  while  the  goldenrods  are  likewise  great  favor- 
ites of  the  insect  world. 

In  Virginia  the  Ceanothus,  or  New  Jersey  tea,  is  in  June, 
says  Banks,  the  most  attractive  enchanter  of  insect  life.  Its 
fragrance  calls  and  caUs  till  around  the  heads  of  white  blossoms 
there  is  an  encircling  halo  of  bees,  flies,  and  beetles,  which  fol- 
low the  enthralling  odor  until  they  rest  on  that  bed  of  white. 
To  stand  neath  the  broiling  sun  and  watch  the  mazy  world 
of  restless  insect  life,  and  to  listen  to  the  hum  of  a  hundred 
tiny  wings  mingled  with  the  sharper  buzz  of  larger  species  are 

261 


THE   FLOWER  AND   THE   BEE 

memories  which  it  is  pleasant  to  recall  on  many  a  wintry  day. 
Banks  collected  382  species  of  insects,  a  larger  number  than  has 
ever  been  recorded  for  any  other  flower :  42  bugs  (Hemiptera) ; 
58  beetles;  165  bees,  wasps,  ichneumon-flies,  ants,  and  saw- 
flies;   and  117  flies. 

Most  of  this  great  group  of  regular  flowers,  comprising  tens 
of  thousands  of  species,  are  perfect  or  hermaphrodite,  that  is, 
possess  both  stamens  and  pistils  and  can  easily  be  self-fertilized. 
Are,  then,  the  visits  of  insects  useless,  and  is  cross-pollination 
needless  .^  Do  the  great  mass  of  the  higher  plants  depend  on 
self-pollination,  and  is  the  much-vaunted  importance  of  in- 
sects as  pollen-carriers  mythical.^  Or  is  the  rank  and  file  of 
the  floral  world  as  dependent  on  insects  for  pollination  as  are 
the  more  highly  modified  forms  described  in  the  previous  chap- 
ters.^ 

In  the  case  of  many  plants  it  can  easily  be  observed  that 
the  life  cycle  of  the  flower  is  divided  into  two  distinct  periods, 
in  one  of  which  the  anthers  ripen,  and  in  the  other  the  stigmas 
(dichogamy) ;  and  consequently  in  the  absence  of  some  agency 
to  carry  the  pollen  they  cannot  produce  seed.  Among  ento- 
mophilous  (insect-pollinated)  flowers  this  occurs  in  the  carrot 
family  {UmhelUferoe)  and  among  anemophilous  (wind-pollinated) 
flowers  in  the  sedges.  In  other  plants  the  pollen  does  not  fall 
on  the  stigmas,  and  still  others  are  self -sterile;  but  we  know  so 
little  about  most  wild  flowers  that  it  is  often  difficult  to  give  a 
definite  answer.  There  is,  however,  a  group  of  trees  and 
shrubs,  and  a  most  abundant  group  it  is,  the  pollination  of 
which  has  been  very  carefully  studied  by  our  agricultural 
experiment  stations — our  domestic  fruits.  So  lavish  is  the 
bloom  of  American  wild  and  domesticated  fruits  that  it  plays 
by  far  the  most  important  part  in  the  floral  landscape  of  June, 
"when  the  white  tide  of  bloom  scuds  across  the  land,  and  the 

262 


BEES  AND   FRUIT-GROWING 

gnarled  apple- trees  along  the  old  stone  walls  are  like  reefs 
swept  by  surf."  Let  us,  then,  consider  what  the  poUination  of 
fruit-bloom  can  teach  us. 

"The  continent  of  North  America,"  says  Hedrick,  "is  a 
natural  garden.  More  than  200  species  of  tree,  bush,  vine, 
and  small  fruits  were  commonly  used  by  the  aborigines  for 
food,  not  counting  nuts,  those  occasionally  used,  and  numer- 
ous rarities."  There  were  whole  forests  of  nut-trees,  as  the 
chestnut,  pecan,  hickory,  acorn,  beechnut,  filbert,  butternut, 
and  nut-pine.  Wild  plums  and  cherries  were  abundant. 
Grapes,  raspberries,  blackberries,  dewberries,  gooseberries, 
currants,  and  elderberries  were  everywhere  laden  with  fruit. 
Great  areas  of  swamp  and  barren  land  were  covered  with 
huckleberries,  blueberries,  and  cranberries. 

Other  fruits  which  can  only  be  named  are:  "The  Anonas 
and  their  kin  from  Florida;  the  native  crab-apples  and  thorn- 
apples;  the  wineberry,  the  buffalo-berry,  and  several  wild 
cherries;  the  cloudberry  prized  in  Labrador;  the  crowberry 
of  cold  and  arctic  America;  the  high-bush  cranberry;  native 
mulberries;  opuntias  and  other  cacti  for  the  deserts;  the  paw- 
paw, the  persimmon,  and  the  well-known  and  much-used  salal 
and  salmon  berries  of  the  west  and  north." 

Since  the  days  of  the  colonies  the  number  of  varieties  of  cul- 
tivated fruits  have  been  greatly  increased  by  hybridizing  and 
selection.  "There  are  now,"  says  Hedrick,  "under  cultiva- 
tion 11  American  species  of  plums  with  588  varieties;  15  species 
of  grapes  with  1,194  varieties;  4  species  of  raspberries  with 
28  varieties;  6  species  of  blackberries  with  86  varieties;  5 
species  of  dewberries  with  23  varieties ;  2  species  of  cranberries 
with  60  varieties ;  and  2  species  of  gooseberries  with  35  varieties, 
or  a  total  of  45  species  with  2,014  varieties."  Coville  has  re- 
cently   shown    that   blueberries    can   be   cultivated,    and   un- 

2C3 


THE   FLOWER  AND  THE  BEE 

doubtedly  many  other  wild  fruits  will  be  domesticated.  Im- 
proved varieties  will  be  obtained  of  June-berries,  elderberries, 
wineberries,  ground-cherries,  cloudberries,  native  mulberries, 
and  many  others.  Hybridizing  can  multiply  new  forms  inde- 
finitely and  yield  such  anomalies  as  the  loganberry  and  the 
blackberry-dewberry. 

To  the  list  of  our  native  fruits  must  be  added  apples,  pears, 
plums,  oranges,  and  other  citrous  fruits  brought  from  the  Old 
World.  In  California  a  beginning  has  been  made  in  the  cul- 
ture of  the  fig,  avocado,  date,  olive,  and  almond ;  and  on  a  small 
scale  the  pomegranate,  guava,  loquat,  and  feijoa  are  being 
tested.  The  mango,  a  delicious  fruit  of  which  there  are  more 
than  500  varieties,  has  been  introduced  into  Florida,  in  the 
southern  part  of  which  there  also  flourish  subtropical  fruits  like 
the  pineapple,  banana,  soursop,  and  cocoanut.  American 
fruit-growing  has  a  wonderful  future  before  it,  and  the  time  is 
speedily  coming  when  the  present  production,  great  as  it  is, 
will  seem  small  both  in  quantity  and  variety.  It  is  impossible 
to  overestimate  the  importance  of  a  knowledge  of  the  pollina- 
tion of  fruit-bloom,  and  of  determining  whether  the  different 
varieties  are  self-fertile,  or  in  the  absence  of  insects  self-sterile 
and  unproductive.  Without  this  knowledge  their  cultivation 
must  constantly  be  attended  by  disappointment  and  loss. 

The  flowers  of  our  common  fruit-trees,  the  pear,  apple,  plum, 
cherry,  peach,  and  orange  are  rotate,  or  wheel-shaped,  nectarif- 
erous, and  attractive  to  a  large  company  of  insects.  On  the 
apple  there  have  been  collected  52  species,  on  the  pear  50,  and 
on  the  sweet  cherry  37,  and  insect  visitors  are  equally  numer- 
ous to  the  bloom  of  most  other  fruit  trees  and  shrubs.  Bees 
are  most  common,  especially  the  honey-bee.  Bumblebees  are 
more  often  found  on  the  blossoms  of  the  apple  than  on  those 
of  the  pear.     There  are  a  variety  of  flies  of  every  size  and  a 

264 


BEES  AND  FRUIT-GROWING 

few  beetles.  Let  us  now  briefly  review  the  investigations  of 
the  experiment  stations  for  the  puri)ose  of  determining  how 
far  the  productiveness  of  domesticated  fruits  is  dependent  on 
insect-poHination. 

About  1875  the  Old  Dominion  Fruit  Company  planted  near 
Scotland  on  the  James  River,  Va.,  an  orchard  consisting  of 
about  22,000  standard  Bartlett  pear-trees.  Although  they 
always  bloomed  heavily  and  were  snow-white  with  blossoms, 
they  never  bore  a  full  crop;  one  season,  when  about  twelve 
years  old,  they  produced  three-fifths  of  a  peck  per  tree,  whereas 
they  should  have  easily  yielded  four  or  five  times  that  quantity. 
Plainly  there  was  something  wrong;  what  was  the  trouble? 

Waite,  who  was  the  first  in  America  to  show  that  many 
varieties  of  orchard-trees  are  self-sterile,  visited  this  orchard 
in  1892,  and  was  able  by  experiment  to  answer  this  question. 
He  noticed  that  in  some  places  where  the  Bartlett  trees  had 
died  out,  they  had  been  replaced  by  trees  of  another  variety, 
as  Clapp's  Favorite  or  Buffuni.     Around  these  trees  the  Bart- 
letts  were  heavily  laden  with  fruit.     Mixed  orchards  in  the 
vicinity  also  bore  well.     He  accordingly  selected  a  number  of 
unopened  buds  and  removed  the  stamens;  and,  after  pollinating 
a  part  of  them  with  pollen  from  Bartlett  trees  and  a  part  with 
pollen  from  other  varieties,  enclosed  them  in  paper  bags.     In 
the  orchard  at  large  a  week  after  the  petals  had  fallen  the  young 
pears  all  dropped  off.     Most  of  the  trees  were  absolutely  barren. 
Of  the  flowers  enclosed  in  bags  not  one  pollinated  with  Bartlett 
pollen  had  set  fruit,  while  a  large  proportion  of  the  crosses  with 
other  varieties  produced  pears.     As  there  were  many  pollinat- 
ing insects  present,  it  is  evident  that  had  there  been  other 
varieties  of  pears  scattered  through  the  great  orchard  all  of  the 
trees  would  have  yielded  well.     The  Bartlett  pear  is  largely 
self-sterile.     (Fig.  115.) 

265 


THE   FLOWER  AND   THE   BEE 

Waite  then  experimented  with  144  pear-trees  belonging  to 
38  varieties.  More  than  half  of  them  when  self-pollinated 
proved  to  be  wholly  or  nearly  self-sterile;    among  which  were 


Fig.  115.     Common  Pear.     Pyrns  communis 

Bartlett,  Anjou,  Clapp's  Favorite,  Howell,  Lawrence,  and 
Winter  Nelis.  Self-fertile  varieties  were  Angouleme,  Bosc, 
Buffum,  and  Flemish  Beauty.  Most  of  the  fruit,  however, 
seems  to  be  the  result  of  crossing,  since  pollen  from  other  varie- 
ties is  prepotent  over  own  pollen  in  the  self-fertile  varieties. 

266 


BEES  AND   FRUIT-GROWING 

Pears  produced  by  crossing  are  larger  and  more  perfect  than 
those  which  come  from  self-fertihzation. 

Like  the  pear  many  varieties  of  apple  are  self -sterile.  Of  87 
varieties  tested  by  Lewis  and  Vincent  in  Oregon,  59  were  found 
to  be  self-sterile;  15  were  self -fertile,  but  gave  better  results 
when  pollinated  by  some  other  variety;  and  13  were  partially 
self-sterile.  Among  the  self-sterile  varieties  were  Bellflower, 
Gravenstein,  King,  Rhode  Island  Greening,  Tolman  Sweet, 
Wealthy,  and  Winesap;  among  the  self -fertile  were  Baldwin, 
Oldenburg,  Shiawassee,  Washington,  and  Yellow  Newton; 
partially  self-sterile  were  Ben  Davis,  Stark,  Spitzenburg,  and 
Yellow  Transparent.  In  the  majority  of  cases  cross-pollina- 
tion is  necessary  to  secure  a  profitable  crop.  Cross-pollinated 
fruit  was  finer  and  larger,  with  well-developed  seeds.  (Fig.  116.) 
Do  not  plant  in  solid  blocks,  says  Waite,  but  plant  mixed 
varieties ;  and  be  sure  that  there  are  sufficient  bees  to  pollinate 
the  blossoms  properly.     (Fig.  117.) 

In  the  A  B  C  of  Bee  Culture  the  writer  has  given  the  follow- 
ing description  of  the  pollination  of  sweet  cherries:  Among 
the  orchard-trees  of  Oregon  the  cherry  ranks  fourth  in  impor- 
tance, being  surpassed  only  by  the  apple,  prune,  and  pear  in  the 
order  named.  A  poor  cherry-crop  affects  the  income  of  many 
persons.  The  rapid  increase  of  the  area  planted  with  cherries 
has  been  followed  by  complaints  that  in  spite  of  the  heavy 
bloom  there  was  not  sufficient  fruit  to  be  profitable.  In  some 
cases  new  orchards  have  never  paid  expenses,  while  old  orchards 
became  less  productive.  xAl though  sorely  perplexed  by  these 
conditions,  the  cherry -growers,  unfamiliar  with  the  mutual  rela- 
tions of  flowers  and  insects,  have  been  slow  to  believe  that  lack 
of  proper  cross-pollination  was  the  chief  cause  of  the  failure  of 
their  trees  to  set  fruit.  But  the  cherry-orchards  of  a  decade 
ago  were  of  small  size  and  of  mixed  varieties;   while  more  re- 

267 


BEES  AND  FRUIT-GROWING 

cently  orchards  of  10  to  100  acres  have  been  phiiited  consisting 
of  one  or  more  of  the  standard  varieties. 

In  order  to  determine  the  cause  and  remedy  these  faihires 


Fig.  117.     Apple-Blossom.     Pyrus  mains 

Gardner  investigated  the  poUination  of  the  sweet  cherries. 
Thousands  of  flowers  were  poUinated  with  their  own  pollen, 
and  insects  excluded  by  bagging.  All  of  the  16  varieties  tested 
proved  to  be  self-sterile.  Ninety  per  cent  of  the  commercial 
plantings  consisted  of  the  Lambert,  Napoleon,  and  Bing,  which 
were  not  only  self-sterile  but  intersterile,  i.  e.,  each  was  sterile 

269 


THE   FLOWER  AND   THE   BEE 

to  its  own  and  the  pollen  of  the  other  two.  Napoleon  when 
planted  extensively  yielded  little  fruit  although  interplanted 
with  Lambert  and  Bing.  But  each  of  these  varieties  is  effec- 
tively polHnated  by  Black  Republican,  Tartarian,  and  Water- 
house.  Thus  without  cross-pollination  no  sweet  cherries  can 
be  raised.     (Fig.  88,  page  181.) 

The  early  settlers  in  the  prairie  States  sometimes  found 
native  plums  growing  along  the  rivers,  which  were  well-flavored; 
but  when  they  transplanted  the  trees  to  tli^ir  gardens  they  be- 
came unproductive.  All  the  varieties  of  "American  plums  are 
self -sterile,  except  the  Robinson,  and  this  is  not  wholly  reliable. 
In  the  woodlands  the  different  varieties  pollinate  each  other. 
The  Japanese  plums  are  also  generally  self-sterile.  Of  the 
European  plums  a  part  appear  to  be  self-sterile,  and  a  part 
self -fertile;  but  no  satisfactory  experiments  have  been  made. 
According  to  Waugh,  who  gave  five  years  or  more  to  the  investi- 
gation of  plum-pollination,  all  the  species  hybridize,  and  all  the 
hybrids  are  self-sterile.  The  majority  of  plums  do  not  bear 
well,  and  most  of  them  set  no  fruit  at  all  unless  there  are  two 
or  three  varieties.  Cross-pollination  by  insects  is  here  again 
a  necessity. 

Nowhere  in  the  world  are  there  so  many  wild  species  of 
grapes  as  in  the  Eastern  United  States.  Foreign  grapes  do  not 
succeed  well  in  this  country  when  planted  outdoors,  and  com- 
mercial grape-growing  is,  therefore,  dependent  on  our  native 
species.  Many  varieties  are  self-sterile.  Of  169  cultivated 
varieties  investigated  by  Beach  in  New  York,  37  were  wholly 
self -sterile,  as  Oneida,  Eaton,  Salem,  and  Wilder;  28  were  so 
nearly  self-sterile  that  the  clusters  were  unmarketable,  as 
Brighton,  Geneva,  Vergennes,  and  Woodruff;  104  varieties  pro- 
duced marketable  clusters  when  self-fertilized,  but  of  this 
number  66  had  the  clusters  loose  and  only  38  yielded  compact, 

270 


BEES  AND   FRUIT-GROWING 

perfect  clusters,  as  Niagara,  Agawam,  Catawba,  Concord,  and 
Isabella.  Nearly  all  the  self -sterile  varieties  are  hyl)rids,  which 
cannot  pollinate  each  other;  but  require  pollination  by  self- 
fertile  varieties  in  order  to  produce  marketable  clusters.  A  vine- 
yard of  self-sterile  varieties  will,  therefore,  produce  no  fruit- 
unless  there  are  a  sufficient  numl)er  of  self-fertile  vines  planted 
among  them  to  pollinate  them  properly.      (Fig.  118.) 

When  the  cranberry-bogs  of  Cape  Cod  and  New  Jersey  bloom 
there  are  hundreds  of  level  acres,  which  are  literally  covered 
with  myriads  and  myriads  of  pinkish-white  blossoms.  The 
flowers  do  not  furnish  much  nectar  and,  although  they  remain 
in  bloom  for  two  weeks,  attract  comparatively  few  insects.  On 
one  side  of  a  cranberry -bog  at  Halifax,  containing  126  acres,  3 
or  4  colonies  of  bees  were  placed.  This  number  was  evidently 
inadequate  to  cover  the  whole  field,  and  it  was  very  noticeable 
that  the  crop  of  berries  was  largest  nearest  to  the  hives,  and 
became  thinner  and  thinner  as  the  distance  from  them  in- 
creased. A  small  i)iece  of  bog  entirely  screened  from  insects  pro- 
duced very  little  fruit.  "In  my  travels  over  the  United 
States,"  says  E.  R.  Root,  "I  never  saw  a  situation  that  demon- 
strated more  clearly  the  value  of  bees  as  pollinators  than  did 
this  piece  of  cranberry -bog." 

More  dissatisfaction  and  loss  are  caused  among  strawberry- 
growers  from  ignorance  of  the  necessity  of  cross-pollination 
than  from  any  other  cause.  A  part  of  the  plants  are  pistillate 
and  a  part  hermaphrodite,  or  possess  both  stamens  and  pistils. 
The  former  remain  sterile  unless  pollinated  by  insects.  As  the 
pistillate  bloom  is  the  more  prolific,  it  is  the  practice  in  field- 
culture  to  plant  three  rows  of  pistillate  to  one  of  staminate.  It 
is  not  at  all  rare,  according  to  Fuller,  to  find  perfect  plants 
which  are  sterile  to  their  own  pollen,  although  the  pollen  is 
perfectly  potent  to  pollinate  other  varieties.     Unless  the  plants, 

271 


THE   FLOWER  AND   THE   BEE 

therefore,  have  been  tested,  it  is  always  better  to  plant  a  num- 
ber of  varieties  in  order  to  avoid  disappointment.  (Fig.  119.) 
The  blueberries  and  huckleberries  have  pendulous,  urn- 
shaped  flowers,  which  are  largely  visited  by  bees.  It  was  long 
supposed  that  blueberries  could  not  be  domesticated,  but  Coville 
has  recently  shown  that  they  will  grow  in  an  acid  soil.  Blue- 
berries have  been  produced  of  the  size  and  color  of  Concord 
grapes.  In  Southeastern  New  Jersey  there  are  thousands  of 
acres  of  peaty,  well-watered,  pine-barrens,  which  are  adapted  to 
their  growth.  Wlien  blueberry-flowers  were  self-pollinated 
only  a  few  berries  were  obtained.  On  some  bushes  not  a  berry 
matured.  Neither  will  plants  raised  from  cuttings  taken  from 
a  single  bush  pollinate  each  other  successfully,  but  the  pollen 
acts  as  though  taken  from  different  flowers  on  one  bush.  Should 
a  blueberry-grower  set  out  a  whole  field  of  plants,  says  Coville, 
from  cuttings  from  a  single  choice  bush,  his  plantation  would 
be  practically  fruitless.  The  cuttings  must  come  from  a  num- 
ber of  not  closely  related  bushes,  and  cross -pollination  by  bees 
is  indispensable. 

But  no  family  can  more  forcibly  illustrate  the  importance  of 
cross-pollination  than  the  gourd  family  {Cucurhitaceoe) ,  which 
includes  the  cucumber,  squash,  pumpkin,  melon,  watermelon 
and  gourd.  The  flowers  are  monoecious,  that  is,  the  stamens 
and  pistils  are  in  different  flowers  on  the  same  plant;  and  in 
the  absence  of  bees  it  is  impossible  for  them  to  produce  fruit 
unless  pollinated  artificially.  In  Massachusetts  cucumbers  are 
very  extensively  raised  for  market  in  greenhouses,  and  there  are 
some  120  persons  engaged  in  this  industry,  making  use  annually 
of  more  than  2,000  colonies  of  bees.  One  grower  who  picks 
10,000  bushels  requires  80  colonies,  while  another  having  some 
40  acres  under  glass  uses  about  the  same  number  of  hives. 
Without  bees  or  hand-pollination  not  a  cucumber  would  be 

272 


/--^ 


Fig.  118.     Brighton  Grape 

Pollinated  by  1,  Salem;  2,  Creveling;  3,  Lindley;  4,  pollen  of  another  vine  of  the  same  variety; 
5,  self-pollmated;  6,  by  Nectar;  7,  Jefferson;  8,  Niagara;  9,  Worden;  10,  Vergennes;  11. 
Rochester.     (After  Beach) 

273 


THE  FLOWER  AND   THE  BEE 


Fig.  119.     Strawberry.     Frag  aria  virginiana 


produced.  Thousands  of  acres  of  cucumbers  are  every  year 
grown  in  the  fields  for  pickle-factories,  and  the  crop  is  wholly 
dependent  on  the  visits  of  bees.  In  a  word,  without  insect- 
pollinators  we  should  have  no  cucumbers,  squashes,  pumpkins, 
or  melons.     (Fig.  107,  page  233.) 

274 


BEES  AND  FRUIT-GROWING 

It  is  an  indisputable  fact  that  a  great  number  of  trees  and 
shrubs  will  not  produce  fruit  unless  cross-pollinated  by  insects. 
At  first  this  service  was  performed  by  our  native  species;  but 
with  the  planting  of  orchards  by  the  square  mile  their  number 
became  wholly  inadequate  to  pollinate  efficiently  this  vast 
expanse  of  bloom.  This  difficulty  is  met  by  the  introduction  of 
colonies  of  the  domestic  bee.  No  other  insect  is  so  well  adapted 
for  this  purpose.  In  numbers,  diligence,  perception,  and 
apparatus  for  carrying  the  pollen  it  has  no  equal.  In  orchard 
after  orchard  the  establishment  of  apiaries  has  been  followed 
by  astonishing  gains  in  the  fruit-crop ;  and  to-day  it  is  generally 
admitted  that  honey-bees  and  fruit-culture  must  go  together. 
"The  importance  of  honey-bees  as  agents  in  cross-pollination," 
says  Gardner,  "cannot  be  overemphasized";  and  one  of  the 
largest  fruit-growers  in  New  Jersey  declares:  "I  could  not  do 
without  bees.  I  never  take  a  pound  of  their  honey.  All  I 
want  them  to  do  is  to  pollinate  the  blossoms.  I  would  as  soon 
think  of  managing  this  orchard  without  a  single  spray-pump 
as  without  bees."  The  fruit-culture  of  the  future  must  be 
largely  dependent  on  the  domestic  bee,  the  only  agency  in  cross- 
ing which  can  be  controlled  by  man.* 

Since  otherwise  numberless  plants  would  produce  no  seed, 
the  beneficial  effects  of  crossing  between  different  individuals 
and  varieties  of  the  same  species  cannot  be  doubted.  It  is  by 
no  means  confined  to  our  wild  and  domestic  fruits,  but  is  of 
very  general  occurrence  among  the  higher  plants.  In  many 
cases  it  is  secured  by  the  separation  of  the  stamens  and  pistils 
by  space,  or  in  different  flowers,  as  in  the  cone  trees  and  many 
deciduous-leaved  trees;    or  by  their  separation  in  time  by  one 

*  The  reader  who  desires  to  follow  this  subject  further  will  find  it  discussed 
at  length  in  an  article  by  the  writer  in  the  A  B  C  of  Bee  Cvltiire  ;  A  Cyclopedia 
of  Everything  Pertaining  to  the  Honey-Bee,  by  A.  I.  and  E.  R.  Root. 

275 


THE   FLOWER  AND  THE  BEE 

maturing  before  the  other,  as  in  many  sedges,  grasses,  and  in  the 
Umbelliferoe ;  or  by  self-sterihty,  as  has  been  illustrated  in  many 
fruit-bearing  plants.  That  in  perfect  flowers  the  pollen  ceases 
to  be  potent  on  its  own  stigma,  or  is  even  poisonous,  as  in  cer- 
tain orchids,  is  presumptive  evidence  that  continuous  inbreed- 
ing is  injurious.  It  has  been  repeatedly  shown  by  experiment 
that  crossing  results  in  the  addition  of  new  characters  and  in- 
creased variability,  of  greater  fertility  or  the  production  of 
more  and  better  seed,  and  in  greater  racial  vigor  of  the  off- 
spring. In  pears  and  apples  crossed  fruit  was  better-colored, 
larger,  and  contained  many  well-developed  seeds,  while  self- 
fertilized  fruit  was  much  smaller  and  seedless  or  contained  only 
vestigial  seeds.  Coville  found  that  self-pollinated  blueberries 
were  smaller  and  later  in  ripening;  and  further  examples  might 
be  multiplied  indefinitely.  The  evil  effects  of  inbreeding  finally 
show  themselves  in  decreased  racial  vigor,  size,  and  fertility. 

Most  of  the  arguments  against  the  value  of  crossing  on  ex- 
amination prove  to  be  specious.  Its  opponents  point  to  the 
commonness  of  close  or  self-pollination;  and  it  is  assumed  that 
the  two  methods  must  be  antagonistic.  In  reality  they  are 
supplementary,  and  the  great  number  of  flowering  plants,  or 
Angiosperms,  is  in  part  due  to  each.  Where  a  species  is  very 
rare  and  is  represented  by  only  a  few  individuals  widely  scat- 
tered, without  self-fertilization  it  would  speedily  disappear, 
since  crossing  would  often  fail  to  occur.  Again,  where  there 
are  large  areas  covered  with  great  sheets  of  bloom  there  are  not 
sufficient  insects  to  cross-pollinate  all  the  flowers.  It  is  better 
for  a  plant  to  be  self-pollinated  than  not  pollinated  at  all.  In 
the  development  of  both  plants  and  animals  there  are  not  a 
few,  which  have  become  adapted  to  special  locations  or  con- 
ditions, where  they  can  live  on  almost  indefinitely  under  self- 
fertilization,  making  no  advance  or  even  slowly  retrograding. 

276 


BEES  AND   FRUIT-GROWING 

But  for  plants  which  are  actively  developing  and  are  forced 
into  fierce  competition  or  are  compelled  to  meet  new  conditions 
crossing  is  indispensable.  Darwin  sowed  crossed  and  self- 
fertilized  seeds  on  the  opposite  sides  of  small  pots  so  that  there 
was  a  struggle  for  bare  existence;  and  the  crossed  plants  grew 
more  vigorously,  bloomed  earlier,  and  more  profusely,  and  pro- 
duced more  seed-capsules.  Thus  the  inbred  races  tend  to  dis- 
appear. 

Crossing  is  by  no  means  confined  to  the  individuals  and 
varieties  of  the  same  species,  but  is  very  common  between  dis- 
tinct species  and  may  occur  between  difi^erent  genera.  It  is 
rapidly  coming  to  be  regarded  as  an  important  factor  in  evolu- 
tion. In  Kerner's  time  more  than  1,000  hybrids  were  known  in 
the  flora  of  Europe,  and  he  fully  believed  that  many  new  species 
originated  in  this  way.  Darwin  had  previously  realized  the 
possibility  that  hybridism  might  have  played  an  important  part 
in  the  history  of  evolution;  but  owing  to  the  general  belief  that 
hybrids  were  almost  invariably  sterile  he  underestimated  its 
significance,  although  he  observed  that  every  intermediate 
stage  existed  between  complete  sterihty  and  complete  fertility. 

^Vhile  hybrids  do  in  general  show  decreased  fertility,  there 
are  thousands  of  cases  in  which  they  multiply  readily  by  seed. 
Jeffrey  has  recently  shown  that  hybrids  among  the  Angiosperms, 
or  flowering  plants,  are  characterized  by  having  a  part  of  the 
pollen  imperfect  or  aborted;  and,  judged  by  this  test,  they  are 
very  common  both  among  wind-pollinated  and  insect-pollinated 
plants.  A  great  many  forms  which  have  long  been  regarded 
by  systematists  as  perfectly  good  species  are  now  recognized 
by  their  aborted  pollen  as  hidden  hybrids.  They  are  especially 
abundant  in  the  rose  family  among  the  roses,  apples,  pears, 
brambles,  and  hawthorns. 

Among  wind-pollinated  flowers  hybrids  are  very  common  in 


THE  FLOWER  AND   THE   BEE 

the  sedges  {Carex),  rushes,  pondweeds,  oaks,  and  birches. 
Among  insect-polhnated  flowers  they  abound  among  the  orchids, 
willows,  violets,  and  roses;  while  more  than  1,000  species  of 
brambles  (Rubus)  have  been  described  in  Europe,  a  large  part 
of  which  are  probably  hybrids.  Many  of  the  so-called  species 
of  Crataegus,  of  which  there  seems  to  be  no  end,  are  the  result 
of  crossing.  They  are  likewise  abundant  among  the  mulleins, 
gentians,  nightshades,  evening-primroses,  thistles,  hawkweeds, 
and  asters. 

There  is  not  a  year  passes  that  cross-fertilization  between 
different  species  does  not  occur  on  a  very  extensive  scale; 
but  owing  to  unfavorable  climatic  conditions  or  intense  com- 
petition few  or  none  even  of  the  fertile  hybrids  survive.  Occa- 
sionally a  hybrid  finds  a  suitable  habitat  and  becomes  a  new 
species,  and  in  the  course  of  the  development  of  the  flowering 
plants  their  number  has  become  very  large.  Hybrids  are  very 
variable  and  the  great  variability  of  the  Angiosperms  is  doubtless 
due  to  the  frequency  with  which  crossing  has  taken  place.  Vari- 
abihty  in  turn  has  hastened  the  development  of  new  species. 
Hybridism  has,  in  the  opinion  of  Jeffrey,  clearly  played  a  large 
role  in  the  acceleration  of  the  evolution  of  the  flowering  plants. 
It  is  still  an  active  agency  the  investigation  of  which  offers  more 
promising  results  than  any  other  factor  in  evolution.  Its  in- 
fluence in  the  transformation  of  species  may  prove  to  be  very 
far-reaching. 


278 
to.  H.  HIUL  LIBRARY 


INDEX 


•' A  B  C  of  Bee  Culture,"  116,  267,  275 

Abulilon,  232 

Aconites,  74,  102 

Adam's-needle,  143 

Adonis,  232;  vcrnalis,  256 

Agassiz,  Louis,  20 

Agropyrum  rcpens,  36 

Ajuga  reptans,  84 

Alaska,  209 

Alder,  common,  21-23,  202 

Alfalfa,  52;   honey  yield  of,  53;   robbed 

by  butterfly  and  bee,  132;   nectarless 

in  the  East,  202 
Allspice,  Carolina,  256 
Almond,  264 
Alpine  flora.  14-16,  134.  160,  208,  238. 

246.  253,  254 
Amaranths,  223 

Ambrosia,  227;  arteinisiifoUa,  38 
Amelanchier  canadensis,  180 
Amentacese,  118 
Armentiferx,  24 
Aments,  22-28 
Andrenid   bees,    108-112,   119;    species 

of,  110,  112,  120 
Anemone,  102,  224;  nectarless,  194 
Anemophilous  flowers,  118 
Angiosperms,  40,  277,  278;    number  of 

species  of,  221 
Angraecum  sesquipedale,  154,  158 
Antaeus,  1 
Antcnnaria,  242 

Anthers,  nutritive,  and  pollination,  200 
Anthobium,  188 

Anthocyanin,  245-247.  250,  252,  256 
Anthophila,  47 
Antirrhinum  majus,  78 
Apetalous  flowers,  colors  of.  221,  250; 

no  blue,  252 
Apple-trees,  blossoms  of,  206,  239 ;  self- 
sterile  varieties,  267 
Aquilegia,  74;  canadensis,  76;   vulgaris, 

76 
Araceae,  167 
Araugia  albens,  177 
Archytas,  104 

Arclostaphglos  Uva-ursi,  84 
Argi/nnis  aphrodite,  96,  130 
Arisspma  triphiiUum,  167 
Aristolochia  sipho,  168 
Artemisia,  227 
Aru7n,  164-168;     conocephaloides,    167; 

maculatum,  164 
Asarum,  256 
Asclepiadacese,  254 
AscJepias,  134,  177 
Ash-tree,  24,  26 
Asinima  triloba,  256 
Asparagus.  228;  beetle,  185 


Asters,  92,  110,  182,  234 
Atropa  belladonna,  84,  228 
Avocado,  264 
Axel.  13 
Azaleas,  248 

Bachelor's-button.  92.  218 

Balsam-fir,  40 

Balsam,  garden,  238;  wild.  98 

Banks,  261,  262 

Barberry,  232 

Bartram,  John,  1,  2 

Basswood.  90,  116,  119,  227.  232 

Bates,  125,  126,  148 

Bayberry-tree,  24 

Bean,  garden,  84,  222;  black  spots  on, 
256 

Bearberry,  84 

Beech-tree,  24,  28 

Bee-flies,  160,  161,  173,  174 

Bee-flowers,  47  etseq.;  colors  of.  64,  65, 
253,  254 

Bee-keepers,  4,  5,  116 

Bees,  competition  among  in  pollen- 
gathering,  115,  118,  119;  diligence 
and  skill  of,  89 ;  effect  of  color  on,  64 ; 
flower  fidehty  of,  92-95.  105-124; 
largest  genus  of  North  American. 
108-112;  idiosyncrasies  of.  122; 
monotropic,  106,  110,  112,  114;  nest- 
building,  121;  oUgotropic,  105-124; 
parasitic,  121;  place  of  pollen  de- 
posit on,  50,  56,  60:  polytropic,  106. 
120 ;  preference  of,  for  certain  flowers, 
114  et  seq.;  rapidity  of  flower  visits 
of,  90;  common  solitary,  123;  tongue 
length  of,  121;  most  valuable  of  pol- 
linators, 47,  89;  life  of  worker,  89; 
insufficiency  of  wild,  118 

Beetles,  46,  47,  178  et  seq.,  202;  de- 
structive to  vegetation,  178;  flesh- 
eating,  186,  188,  189;  flowers  visited 
by,  108,  180  et  seq.;  on  fruit-trees, 
265;  habits  of,  178,  180;  of  httle  im- 
portance in  flower-pollination,  192; 
living  on  single  plant  species,  185; 
number  of  species  of,  180;  plant- 
eating,  186,  189-192;  poUen-flowers 
visited  by,  182;  with  suctorial  tongue- 
192;  wood-boring,  190-192 

Belladonna,  84,  228 

Bellflower,  114,  244;  family,  blue  in, 
253,  254 

Bidens  aristosa,  116,  121 

Bilabiate  flowers,  182 

Bilateral  flowers,  250 

Birch-tree,  24,  28 

Bird-flowers,  56,  76,  77;   color  of,  136 

Bird- winged  butterfly,  125 


279 


INDEX 


Bitter  cress,  230 

Black  bees,  194,  196 

Blackberries,  number  of  varieties  of,  263 

Bladderwort,  19 

Blister-beetle,  185,  186,  192 

Bloodroot,  194 

Blue,  liighest  color  in  floral  world,  248, 
250 

Blueberries,  64;  domesticated,  263,  272 

Blue  flag,  124,  134;    beetle,  124,  185 

Blue  flowers,  136,  138,  221-224,  248- 
254;  coloration  of,  245;  number  of, 
248 

Bluet,  203 

Bombus,  122;  americanorum,  71;  fer- 
vidus,  52,  71,  90;  hortorum,  71;  ter- 
narius,  94;  terrestris,  71;  terricola, 
80,  100,  214;   vagans,  80,  90,  98,  106 

Bomhyliidx,  173,  174 

Bonnier,  212 

Borage,  60,  64,  213,  250 

Botanical  garden,  first  American,  1,  2 

Bouncing  bet,  151 

Brambles,  278 

Braun,  Alexander,  20,  21 

Brilliancy  of  flowers,  238 

Brown  flowers,  256 

Brown,  Robert,  12 

Buckwheat,  116,  227;  nectar-secretion 
of,  89,  90,  202;  red-flowered,  247, 
248 

Bugle,  84 

Bumblebee-flowers,  56,  70-88;  primi- 
tive form  of,  84,  86 ;  punctures  in,  80 ; 
typical  wild,  78 

Bumblebees,  52,  194;  captured  by 
spider,  104;  maxillae  of,  96;  nec- 
taries punctured  by,  96-102;  pol- 
lination of  red  clover  by,  70-72; 
queen,  84;  species  of,  71;  tongue  of, 
74,  90 

Bunchberry,  203 

Burroughs,  200,  209 

Butter-and-eggs,  84,  86,  232 

Buttercups,  60,  92,  172,  194,  222,  224; 
English,  230;  famUy,  250;  colors  of, 
232 

Butterflies,  47,  212;  blue,  134;  brilUant 
markings  of,  125,  126;  captured  by 
spider,  104;  flowers  robbed  by,  132, 
134;  flowers  visited  by,  96,  128-138; 
number  collected  on  flowers,  126; 
number  of  species  of ,  126;  punctures 
in  plant-tissues  made  by,  102;  red, 
134,  247 

Butterfly  -  flowers,  125  ct  seq.;  Alpine, 
134;  best  known,  128,  130;  char- 
acters of,  130;  colors  of,  134-138; 
origin  of,  158,  159;  red,  134,  136; 
small  number  of,  132 

Byturus  unicolor,  188 

Cabbage-butterfly,  96 
Cacti,  Mexican,  146 
Cactus,  224 
Calceolaria,  56 

California,    bees   of,    92,  119;     orange- 
bloom  in,  115 
Calla-Uly,  168 


Calla  palustris,  164 

CalUphora,  161 

Calycanthus,  256 

Calypso  borealis,  84 

Campanula,  244;  americana,  114 

Campanulacex,  253,  254 

(\inna,  228 

Canterbury,  72 

Capri  foliaceae,  194 

Carabidx  Lebia,  188 

Caraway,  242 

Cardamine,  230 

Cardinal-flower,  76,  248 

Carpet-beetle,  188 

Carrion,  beetle,  182;  flower,  162;  fly, 
161,  212 

Carrot  family,  242,  261,  262 

Carrotin,  228,  256;  flowers  owing  color 
to,  232;    light's  effect  on,  230,  231 

Caryophyllacese,  130 

Cassia,  200;  Chamseclirista,  116 

CastiUeja,  203 

Catchfly,  butterfly-flower,  128;  long- 
flowered,  151;  night-flowering,  150; 
nodding,  151 

Caterpillar,  forest,  115 

Catkins,  staminate  and  pistiUate,  22-28 

Ceanothus,  190,  261;  americanus,  180 

Cedar-tree,  38 

Cinlaurca  cyanus,  92,  218 

Century-i)lant,  90 

Ccrambycidse,  190 

Ccratopoqon,  166 

Ccrcus,  146 

Cerinthe  alpina,  84 

Cctimia,  178,  182 

Chauliixinalhus,  188 

Checker  berry,  64 

Chclone  ylabra,  56,  78 

Chenopods,  223 

Cherries,  188;  ground,  194;  pollina- 
tion of  sweet,  267-270;  varieties, 
269,  270 

Chestnut,  232 

Chickweed,  244 

Children,  love  of  flowers  among,  2,  3 

ChlorophyU,  226,  228,  256;  elements 
in,  231;  light's  effect  on,  230 

Chokeberry,  180,  190 

Choke-cherry,  180 

Christmas  rose,  244 

Clirvsanthemum,  236 

Chrysomilida',  189 

Chri/sopsis,  234 

Cin(iuefoils,  222 

City  sc|uares,  gardens  in,  3 

Clo'ylimia  rirginica,  110 

Clcistoganiic  (lowers,  48 

Clematis,  garden,  196;  wild,  194,  196; 
Jackmanni,  196,  219;  virginiana,  196 

Cleome,  121;  serrulata,  112;  spinosa,  90 

Click -beetle,  189 

Clintonia  borealis,  227 

Clover,  color  change  in,  56;  colors  of, 
64;  nectarless,  202;  red,  48,  70-72; 
white,  56,  119,  202;  yellow,  56 

Cobsea  scandens,  218 

Coccinellida;,  188 

Cockerell,  112 


280 


INDEX 


Codling-moth,  177 

Coleoptera,  178  et  seq. 

CoUetes,  112,  120 

Collinson.  Peter,  2 

Colors  of  flowers,  8-11,  48,  64.  65,  134- 
138,200;  changes  in,  56,  222,  223,  230, 
236,  237,  244,  250;  conspicuous.  203 
et  seq.;  contrast  in,  206-216;  deter- 
mined by  plant  pigments,  238;  dis- 
tribution of,  221-224;  insect  prefer- 
ences in,  212;    variety  of,  92,  208 

Columbines,  64.  194,  222;  bumblebee- 
flowers,  74,  76;  nectar-srcretiou  of, 
98;  punctured  by  bumblebees,  98. 
99;  reversion  to  regular  form  of,  86; 
wild,  76.  248 

Composiise,  110.  112.  223.  234;  bee 
visitors  of.  120.  121;  beetles  on.  180. 
182;  blue  flowers  of,  253.  254;  but- 
terfly visitors  of.  132.  138;  color  in, 
242;  red-flowered.  248 

Cone  trees.  38-46 

Conifer  ales,  40 

Conifers.  40.  46 

Conspicuousness.  flower,  advantages 
of.  209-220;   significance  of,  9-12 

Coquillet,  144 

Cornels,  180,  190 

Cornus,  180 

Corydalis,  102 

Cotton,  116 

Coville.  263.  272.  276 

Cow-wheat.  56 

Cranberries,  bee-pollination  of.  271; 
number  of  varieties  of.  263 

Crataegus.  278 

Crepis  aurea,  134 

Crocus,  moth-pollinated,  154 

Cross-pollination,  12,  262;  adaptations 
favoring,  26,  28;  between  different 
species,  277,  278;  in  fruit-culture. 
275-278 

Croton  texensis,  112 

Crowfoot,  water.  236 

Crownbeard.  242 

Cucumbers,  bee-pollination  of,  272,  274 

Cucurbita,  maxima,  214;  Pepo,  114 

Cucurbitaceae,  272 

Cudweed,  242 

Currant.  188;  flowering,  223;  golden. 
237 

Custard-apple.  256 

Cycadeoidea,  224 

Cycadophytes.  46 

Cycads,  40,  46 

Cyclamen,  238 


Dahlia,  232;  variabilis,  92 

Daisy,  203 

Dance-flies,  110,  174,  177 

Dandelions,  203,  232 

Daphne  striata,  134 

Darwin,  (Miarles,  10-14,  17,  70,  86,  102, 

158,  210,  236,  252,  277 
Darwin,  Francis,  12 
Dates,  264 
Datura  arborea,  139 
Davis,  J.  Ainsworth,  17,  150 


Dead-nettle.  56,  102;  nectar-guides  on. 
68 

De  CandoUe,  252 

Delphinidin,  247 

Delphinium,  14:;  cardinale,  252;  elalum. 
74 

Delpino.  13.  178 

Dendrobium  normale,  86 

Dermestids.  188 

Desmodium,  56,  198 

De  Vries.  150 

Dewberries,  number  of  varieties  of,  263 

Dianthus,  arenaria,  151;  atroruber,  134; 
barbatus,  128;  deltoides,  128;  super- 
bus,  134;  sylvestris,  134 

Di  centra,  102 

Dicotyledonous  flowers,  221,  252 

Diervilla  trifida,  84 

Diptera  flies,  160,  171 

Docks,  36 

Donacia,  piscalrix,  108.  185;    rufa,  108 

Dracocephalum,  84 

Dragon-fly.  104 

Dragon's-head.  84 

Dutchman's-pipe.  168.  256 

Eimer.  126 
Elateridae,  189 
Elderberries,  188,  194,  200 
Elecami)ane,  96,  132 
Elm-tree,  24,  26,  28-30,  202 
Emerson,  9 
Empididae,  110,  174 
Empis  rufescens,  19,  174 
England,  red  clover  in,  70 
Entomophily,  231 
Epcolus,  112 

Epicauta  pennsylvanica,  185 
Epilobium  molle,  96 
Erica  carnea,  132,  134 
Eristalis  lenax,  173 
Eucalyptus,  92 
Evergreen  trees,  38-46 
Everlasting-flower,  216,  242 
Evolution,  floral.  86.  222 

"Facts  for  Darwin."  14 

"Fertilization  of  Flowers.  The."  13.  14 

Fertilization.     See  Pollination 

Feijoa.  264 

Fig.  264 

Figwort  family.  48.  56,  60,  194,  242, 
253;  colors  in,  64 

Fireflies.  188 

Fir-tree.  38.  40.  46 

Flag,  blue,  134;    beetle  on,  124,  185 

Flies,  47,  104,  108,  160-177,  202,  264 
habits  of,  in  visiting  flowers,  96 
species  of  two-winged,  160.  161 
stupid.  160;  syrphid.  19,  36,  96,  160. 
161,  172,  173 

Florida,  "Big  Sawgrass"  in,  116 

Flower-food,  suri)lus  of,  115 

Flowers,  adaptations  of.  for  effecting 
pollination.  68.  69;  dependence  of. 
on  bee  visitors,  48;  two  periods  of 
life  cycle  of,  262;  influence  of,  3-6; 
how  iDOwer  of  secreting  nectar  is  lost 


281 


INDEX 


by,  201,  202;  metamorphosed  buds, 
224;  poetry  on,  6,  7 

"Flowers  of  the  Alps,"  16 

Flv-flowers,  56,  161-177 

Forests,  24-28;  evergreen,  38-46; 
hardwood,  28 

Forget-me-not,  10,  223,  237,  250 

Forsythia,  232 

Foxglove,  56,  84 

Fragaria  virginica,  112 

Freidank,  226 

Fruit-growing,  261  et  seq.;  future  of 
American,  264 

Fruits,  native  American,  262-264;  de- 
pendence of,  on  insect-pollination,  4, 
265  et  seq.;  insect  visitors  to,  264; 
value  of  cross-pollination  of,  276 

Fruit-trees,  insects  visiting,  264 

Fuchsia,  224 

Funnel-formed  flowers,  64 

Galeopsis  TetrahU,  56,  68 

Gall-berry,  115 

Gamopetalous  flowers,  colors  of,  221, 
260;  blue  color  among,  253 

Gardenia,  154 

Gardner,  269,  275 

Gentians,  64,  182,  234;  blue  of,  254; 
closed,  80,  82;  fringed,  80,  82;  moth- 
pollinated  varieties,  154 

Geometridae,  140 

Georgia,  gall-berry  in,  115 

Geranium,  wild,  bee  of,  110;  macu- 
latum,  112 

Gerardia  purpurea,  84 

Gibson,  177 

Gill-over-the-ground,  84 

Ginger,  wild,  256 

Gladiolus,  84 

Clcchoma  hederacea,  84 

Globularia,  138 

Gnaphalium,  242 

Gnathiuvi,  192 

Gnats,  18 

Goethe,  224 

Goldenrod,  90,  92,  116,  119,  121,  261; 
bee  visitors  of,  110,  112;  beetles  on, 
180,  182,  185,  188,  189;  pollen  and 
nectar  yield  of,  120;  species  of,  dis- 
tinguished by  honey-bees,  94,  95; 
valuable  honey-plant,  236 

Gooseberry,  228,  256;  number  of  vari- 
eties of,  263 

Gourd  family,  cross-pollination  in,  272 

Graenicher,  108,  120,  174 

Grapes,  punctures  in,  100,  102;  num- 
ber of  varieties  of,  263;  self-sterile 
varieties,  270,  271 

Grasses,  202,  223;  opening  of,  32,  36; 
wind-pollination  of,  30-36 

Gray,  Asa,  13,  40,  92,  204,  238 

Green  flowers,  214,  216,  221-228;  color 
pigments  of,  224,  226,  228;  insect- 
pollinated,  227;  large,  228;  small, 
227 

Greenland,  flower-color  in,  237,  238 

Groundsel,  234 

Ground,  bee.  108,  194;   beetle,  188 


Guava,  264 
Gymnosperms,  40 

Habenaria  psy diodes,  154 

Ha-ckel,  Ernst,  70 

Halictoides  novae-anglise,  105 

Halictus,  122;  nelumbonis,  108 

"Handbook  of  Flower  Pollination,"   16 

Hawk-moth  flowers,  139  et  seq.;  char- 
acteristics of ,  150,  151;   exotic,  154 

Hawk-moths,  126,  131,  140  et  seq.; 
characteristics  of,  146,  148;  clear- 
winged,  140,  148;  value  as  polli- 
nators, 146 

Hawk's-beard,  134 

Hawk  weed,  134 

Hazelnut-trees,  24,  202 

Heart's-ease,  116 

Heath,  crimson,  132,  134,  234,  247 

Hedge-nettle,  56,  65 

Hedrick,  263 

Heeria,  200 

Helianlhus,  121;  annuus,  112 

Helichrysuni  bracteatum,  216 

Hellebore,  false,  227 

Helleborus  niger,  244 

Helophilus  conostomus,  19 

Hemans,  Felicia,  139 

Hemaris,  148 

Hemlock,  water,  242 

Hemp,  36 

Hemp-nettle,  56,  68 

Henbane,  black,  84 

Hepaticas,  194,  206,  224 

Hermaphrodite  flowers,  262 

Heteranthcra  rcyiiformis,  200 

Helerocampa  gutlivilta,  115 

Hibiscus  mutabilis,  244 

Hickory-nut  tree,  24,  202 

Hieracium  aurantiacum,  134 

Ililara  atra,  108 

Hildebrand,  13,  252 

HoUyhocks,  236 

Honey,  first  of  the  season,  24;  nectar 
required  for  pound  of,  89;  produc- 
tion possibilities  of  resources  of 
coimtry,  115,  116 

Honey-bees,  23,  89  et  seq.,  202,  212,  264; 
captured  by  spider,  104;  choice  of 
conspicuous  objects  by,  216;  color 
distinguished  by,  217,  218;  no  flowers 
adapted  to,  86;  value  of,  in  fruit- 
culture,  275;  nectar  stolen  by,  80,  98, 
132;  plant-tissues  punctm"ed  by,  102; 
tongue  of,  86,  88 
Honeysuckle,  194,  222;  bush,  84,  232, 
237;  climbing,  148,  150,  223;  fly,  84, 
98,  232;  moth-polhnated,  148,  150, 
223;  punctures  in,  98;  trumpet,  76, 
248;  Tartarian,  84;  varieties  polli- 
nated by  queen  bumblebee,  84 
Hops,  36 

Horehound,  water,  96 
Horizontal  flowers,  60-64 
Hornbeam,  24 
Horse-chestnut,  60,  84 
Horse-flies,  161 
Hover-flies,  160,  171-173,  212 
Huckleberries,  272;  red  flowers  of,  247 


INDEX 


Humanity  a  part  of  nature,  8 
Humboldt,  (i 

Hummin^-l)ird  flowers,  7«i,  77 
Humming-birds,  80,  150,  212,  247,  248 
Hunt,  Leigh,  7 
Huxley,  71,  254 
Hyacinth,  252;  water,  105 
Hybridizing    of    fruits,    203.    264;     of 

flowering  plants,  277,  278 
Hybrids,  277,  278 
Hydrangea,  wild,  189 
Hymenoptera,  160 
Il'liosciiamus  niger,  84 

Ilex  glabra,  115 

Impaticns  biflora,  78,  80,  98,  232 

Indian  corn,  30,  202 

Indian-pipe,  206 

Indian  turnip,  167,  168 

Ingalls,  30 

Insects,  pollinating,  4,  6,  46,  160,  224, 
227,  262;  color  preferences  of,  212; 
difficulty  of  classifying,  17;  value  of 
acquaintance  with,  17-19;  visiting 
only  one  species  of  flowers,  124 

hiula  Ilclcnium,  96,  132 

Iowa,  honey  production  in,  115,  116 

Iris  versicolor,  124,  134 

Irregular  flowers,  bee,  48-64;  white, 
222,  244;  yellow,  232,  234 

Ivy,  Boston,  228 

Jack-in-the-pulpit,  167,  168 
Jamestown  weed,  154 
Jeffrey,  277,  278 
Jessamine,  232 
Jewelweed,  78,  80,  232 
June-bugs,  190 
Juniper-tree,  46 

Kalmia,  248;  lalifolia,  204 

Kerner,"  Anton,   17,  36,   114,   136,   144, 

148,   182,  208,  227,  246,  277 
Kerria  japonica,  232 
Kingsley,  Charles,  3,  4 
Knuth,  Paul,  16,  180,  182 
Kronfeld,  74 

Labiaise,  56,  64 

Laburnum,  102 

Lady-bugs,  188 

Lamium  album,  56,  68 

Lantana,  223.  244 

Larch-tree.  38 

Larkspur,  48.  102,   132,   194,  222,  250, 

252;    bee,  74;    bumblebee-flower,  74; 

regular,  86;    white  variety  of,  244 
Lathyrus  odoratus,  50 
Laurent,  237 
Leaf-beetles,  189 
Leaf-cutting  bee,  52,  122 
Leaf-green.  226-228 
Leaf-roller  moth,  140 
Leaf-yellow,  228 
Leaves,  green,   224;    red,   246;    white, 

237;  yellow,  228 
Lechea,  227 


Leguminosae,  196 

Lemon,  232 

Lepidoptera,  126,  159 

Lewis,  267 

Lily,  222;   bee,  130,  131;  butterfly,  130; 

hawk-moth,     131;     moth-pollinated, 

154;  varieties,  130,  131.  134,  154 
Linaria  vulgaris,  84,  86,  232 
Linden,  189 
Lindley,  252 
Linnaea  borealis,  18,  174 
Lobelia  cardinalis,  248 
Locust,  102 
Loew,  Ernst,  17,  106 
Longfellow,  6 
Lonicera,  cwrulea,  84;     ciliata,  84,  98; 

Pcrichimenum,  148;   Tartarica,  84 
Loosestrife,  194,  196;  bee  of .  112 
Loose  wort,  56 
Loquat,  264 
Lucilia,  161 
Lungwort,  84,  174,  250 
Lupine,  199-201,  206 
Lupinus,  199;  subcarnosus,  200 
Li/caena,  136 
Lychnis,  128,  134;  evening,  151;  white, 

151 
Lycopus  europseus,  96 
Lysimachia  vulgaris,  112,  196 

Mabie,  Hamilton  W.,  7 

Macrodactylus  subspinosus,  190 

Macroglossa,  146,  148 

Macropis  ciliata,  112,  196 

ISIagnoha.  17S.  182,  242 

Maidenliair-tree,  46 

Maine,  l)eesin,  119;   Perdita  bee  in,  112 

Mallow  family,  red  flowers  of,  247,  248 

Malvidin,  247 

Mango,  264 

Marigold,  marsh,  172,  185 

INlaples,  in.sect-pollination  of.  21;  red. 
238;  striped,  232 

Mason  bees,  194 

IMeadow-rue,  36 

Meadow-sweet,  180 

Measuring  moth,  140 

Medina,  Ohio,  apiaries  at,  72 

Megachile  campanulae  114;  mela- 
nophsea.  122;  laiimanus,  52 

Megarrhinus,  161 

Melampyrutn,  56 

Melissodes,  112,  120 

Meloidsp,  192 

Melon,  272,  274 

IMemnon,  statue  of,  32 

Mrsoqrapta  germinata,  96 

IMidges,   166 

Milkweeds,  254;  pollinating  mecha- 
nism of,  177 

Mint  family,  48,  56,  60,  242.  253; 
colors  in,  64 

Misumciia.  asperata,  104;  vatia,  104 

IMitchell.  Donakl  G.,  2 

]Molucca  balm.  84 

Moluccella  la'vis,  84 

Monarda,  134;  media,  203;  punctata, 
121 

Monkey-flower,  56,  253 


283 


INDEX 


Monk's-hood,     250,     254;      bumblebee 

flower,  74;    regular,  86 
IVIonocotyledonous   flowers,    colors    of, 

221,  257;    blue  among,  252 
Mononychus  vulpeculus,  124,  185 
ISIosquitoes,  161 
Moth-flowers,  158,  159 
Moths,  two  groups  of,  140;    nocturnal, 

132;     140  et  seq.;    number  Usted  as 

flower-visitors,  126;  number  of  species 

of,  126;    plant-tissues  punctured  by, 

102 ;   species  of  smaller,  140 ;    tongue 

of,  128 
Moimtain-laurel,  204 
IMueller,  Fritz,  13,  14,  148 
Mueller,  Hermann,   10,   12-16,  69,  80, 

98,  102,  130,  132,  160,  172,  174,  178, 

210,  212,  247 
Mulleins,  194,  195 
Musca,  161 
INIustard,  224,  236;  yellow  and  white, 

232 
Myosotis,  10;  versicolor,  223,  237 

Nasturtium,  garden,  78,  90,  228,  232; 

bumblebee-flower,  77 
Nectar,  depth  concealed,  124,  158,  159; 

waste  of,  115,  116;    weight  of,  116 
Nectar-guides,  65,  68 
Nectaries,  variation  in  length  of,   158, 

159 
Nectarless  flowers,  56,  102,  202,  219 
Needham,  185 
Nemognatha,  182,  192 
Nettles,  36,  38,  56,  223;    nectar-guides 

on,  65,  68 
New  England,  andrenid  bees  in,  120 
New  Jersev  tea,  180;    beetles  on,  189, 

190;    insect  visitors  of,  261,  262 
New  Mexico,  species  of  Perdita  bee  in, 

112 
New  Zealand,  red  clover  culture  in,  71 ; 

flies  in,  160 
Nicotiana,    longiflora,    154;      noctiflora, 

154 
Night-blooming  cereus,  146 
Nightshade,  196,234;  moth-poUinated, 

154;  nectarless,  194 
Noctuidae,  140 
Nocturnal  flowers,  130,  139  et  seq.,  146; 

color  of,  206 
Nymphsea  advena,  106,  108,  230 

Oak-tree,  24,  28 

Odors,  floral,  114;  unpleasant,  161-164 

(Enoihera,  biennis,  150;  laciniata,  236 

Old  Dominion  Fruit  Company,  265 

Olive,  264 

One-sided  flowers,  48-64 

Orange,  nectar-secretion  of  bloom  of, 
115;    punctured  by  moth,  102 

Orchids,  12,  13,  48,  159,  194,  222,  242; 
Madagascar,  154,  158;  moth-polh- 
nated,  154,  158;  nectarless,  102 
regular  form  in,  86 

Orchis,  color  of,  64;  blue,  136,  252; 
greenish  or  white,  132;  purple- 
fringed,    132;     showy,    84;     globosa, 


134;    Habenaria,  132;   maculata,  102; 

morio,  102;  spectabilis,  84 
"Origin  of  Species,"  13 
Ornithoptera,  125 
Overton,  245,  246 
Owlet  moth,  140 

Painted-cup,  76,  203 
Pansy,  48,  237,  252 
Panurginus,  112 

Panurqus,  120 

Papilio  asterias,  104 

Papilionacese,  50,  64,  250 

Parnassia  caroliniana,  112,  220 

Parsley,  water,  242 

Parsnip,  wild,  242 

Paul,  Jean,  125 

Pea  family,  48,  50-56,  60,  222,  242.  250; 
change  in  position  and  color  of,  56; 
colors  in,  64;  form  of,  50 

Peaches,  punctures  in,  102 

Pear,  value  of  conspicuousness  of,  212, 
213;  value  of  insect-pollination,  265; 
Bartlett,  265 

Pear-trees,  self-sterile  varieties,  266 

Pedicularis,  56;  sylvatica,  84 

Pelargonidin,  247 

Penny-cress,  230 

Perdita  bee,  120;  -flowers  visited  by, 
112,  121;  species  of,  112 

Perfect  flowers,  262,  276 

PhilUps,  Doctor,  4,  116 

Phlox,  132,  250 

Physalis,  194 

Pluiteuma,  136 

Pliytophagous  beetles,  186,  189-192 

Picea  marinna,  40 

Pickerel- weed,  bee,  105,  106;  nectar- 
guides  on,  65;  insects  attracted  by, 
106;  number  of  bee  visits  to,  per 
minute,  90;  white,  244 

Pigweed,  36,  223 

Pinch-trap  flowers,  177 

Pine-trees,  pollen  of,  40,  45,  46;  red, 
40,  46;  white,  38 

Pinkroot,  248 

Pinks,  64,  227;  butterfly-flowers,  128, 
130,  134;  moth-pollinated,  151;  red, 
247;  white,  234,  244 

Pinus  sylvestris,  182 

Pin  weeds,  227 

Pitfall-flowers,  164,  167,  168 

Plateau,  Fehx,  173,  212,  214,  216 

Plums,  Amei'ican  and  European,  270; 
ground,  203;  Japanese,  261,  270; 
punctures  in,  102;  number  of  vari- 
eties of,  263 

Pogonia  ophioglossoides,  84 

Pollen-flowers,  194-202;  anthers  of, 
200;  devices  of,  for  placing  pollen  on 
insects,  196-200;  variety  in  colora- 
tion of,  200 

Pollination,  cross,  12,  26,  28;  insect,  4, 
6,  46,  160,  224,  262;  self,  26,  28,  30, 
224,  262;  wind,  20-46 

Polygala,  244 

Pohjgalaceae,  254 

Polygonum  sagiUatum,  96 

Polypetalous   flowers,    colors    of,    221, 


284 


INDEX 


258,  259;  rarity  of  blue  among,  252, 
253 

Pomegranate,  264 

Pondwced,  36 

Pontedcria  cor  data,  90,  105 

Poplar-tree,  24 

Poppies,  194,  224;  bee  visitors  of,  196; 
colors  of,  248;  scarlet,  228 

Portulaca,  238;  grandiflora,  218 

Potato-bug,  189 

Potatoes,  beetles  on,  185 

Primrose,  132,  134,  234;  evening,  150, 
232,  247 

Primula  acaule,  134 

Prison-flowers,  164,  166 

Pronuba  moth,  140;   habits  of.  143-145 

Prosopis,  121,  194 

Protcaccae.  203 

Prunus  virqiniana,  180 

Psi/choda,  168 

Pulmonaria  officinalis,  84,  174 

Pulse  familv,  196,  199,  201 

Pumpkin,  272,  274;  bee  of  field,  114 

Punctures  in  corolla-tubes,  96-102 

Purple  flowers.  221-224,  254-256 

Purslane,  water,  227 

Pussy-willow,  change  in  manner  of  pol- 
lination of,  23,  24;  insects  visiting, 
110 

Pyrus,  arbuti folia,  180;  communis,  212 

Queen  of  the  Night,  146 
Quitcli-grass,  36 

Ragweed,  36,  202,  223,  227 

Rainfall,  effect  of,  on  red  clover,  72 

Raspberries,  116,  188;  number  of 
varieties  of,  263 

Red,  effects  of,  247 

Red  clover,  70-72,  102 

Red  flowers,  134,  136,  221-224,  245- 
248;  and  blue,  252;  coloration  of, 
245-248;  distribution  of,  247,  248; 
more  primitive  than  blue,  247 

Regular  flowers,  86,  261,  262 

Retrogression  in  flowers.  227,  237,  242, 
244,  254 

Rhododendron,  248;  maximum,  203 

Khodora,  9;  canadensis,  84 

Rhi/ncophora,  190 

Ribcs  aurrum,  223,  237 

Riley,  140,  144 

Rock-maple,  227,  228,  232 

Rock -rose,  194 

Rodrique,  237 

Root,  E.  R.,  116,  271,  275 

Rose,  60,  64,  227,  228,  232,  250;  beetles 
on,  182;  insects  visiting,  194;  never 
blue,  250,  252;  pollen-flower,  194, 
200;  no  nectar  secreted  by.  193.  194; 
red,  247;    yellow  and  white,  232 

Rose-chafers,  190 

Rove-beetles,  188 

Rubus,  278 

Riunex  Acrtosella,  104 

Rushes,  202,  223 

Sages,  56,  62,  84.  119 
St.-John's-wort,  194;   colors  of,  234 


Salix.  23.  24,  110,  121;   pollen  and  nec- 
tar yield  of,  119 
Salvia,  48;  pratensis,  84 
Sand-pink,  151 
Sandwort,  244 
Saponaria,  ocymoides,  128;     officinalis, 

151 
Sarcophaga,  161 

Sarcophagous  beetles,  186,  188,  189 
Saxifrages,    dots    on    coroUa    of,    164; 

varieties  of,  164 
Scaraba?ids,  189,  190 
Scaraba^us,  190 
Scarlet  runner,  84,  94;    punctures  in, 

100;   wliite  variety  of.  244 
Scopaliu  atropoides,  84 
Scropliulariacea\  56,  64,  194 
Scutellaria  gakriculata,  98 
"Secret  of  Nature   in   the   Form    and 

Fertihzation  of  Flowers  Discovered," 

9—12 
Sedges,  202.  223,  262;   wind-pollinated, 

30-36 
Sedu7n,  acre,  238;  purpureum,  238 
Self-pollination,    224,    262;     of  grasses 

and  sedges,  30;   prevention  of,  26,  28 
Senecio,  234;  Douglasii,  112 
Shadbush,  180 
Sham-nectar  producers.  102 
Shoe-flower.  56 

Shrubs,   blossoms  of.   239;    deciduous- 
leaved.      223;       red-flowered.      248; 

yeflow-flowered,     232,     234;      wind- 
pollinated.  24 
Silene,    134;     acaulis,    128;     longi flora, 

151;   nocti flora,  150;   nutans,  151 
Silver-winged  butterfly,  96 
Skullcap,  56,  253;  punctures  in,  98 
Skunk-cabbage,  163,  164 
Smilax,  227 
Smith.  110 
Snapdragon,  56,  62,  63,  232,  244.   254; 

bumblebee-flower,   78;    nectar-guides 

on,  65;  regular  form  of,  86 
Snout-beetles,  190 
Soap  wort,  128 
Solanaccsf,  194 
Sohinum  Dulcamara,  196 
Soldier-b(>etl(\  1S8,  189 
Solidagn,  110,  121,  234;     bicolor,  94,  95; 

graminifolia,94:;  juncea,  112;  rugosa, 

94 
Sorrel,  36,  104,  223,  238 
Spanish  bayonet,  124;  moth-pollinated, 

140.   143 
Speedwells,  56,  172 
Sphingidse,  126,  140 
Spider-plant,  90 
Spiders,  crab,  102-104 
Spiraea,  92,  190,  194;    salicifolia,  180 
Sprengel,  Christian  Conrad,  9-12,  102, 

210 
Spring-beauty,  110 
Spruce-tree,  38,  40 
Squash.  232,  272,  274;    value   of  con- 

spicuousness  of.  214 
Squash-bug,  189 
Stachys  erecta,  56,  65 
Stahl,  230.  246 


285 


INDEX 


Staphi/Iinidse,  188 

Starch,  226.  227 

Stickseed,  250 

Stonecrop,  238 

Strawberries,  60;  bee  of,  112;  insect- 
pollination  of,  271 

Sumac,  122 

Sunbirds,  247 

Sunflower,  92,  112,  182,  232 

Sweet-fern,  24 

Sweet  pea,  50,  51,  217 

Sweet-william,  223,  242;  butterfly- 
flower,  128 

Syrphid  fly,  19,  36,  96,  160,  161,  171, 
172;  resemblance  of,  to  bees  and 
wasps,  173 

Tear-thumb,  96 

Tcbanidse,  161 

Tcncidse,  140 

Texas,  State  flower  of,  200,  206 

Thaliclruyn,  194 

Thalspi,  230 

Therioplectes,  104 

Thistles,  132,  182,  232;  Canada,  96; 
colors  of,  234 

Thomisid3e,  102,  104 

Thomson,  160 

Thorn-apples,  139 

Thorn-bush,  228 

Thoroughwort,  132,  138 

Tick-trefoil,  198,  199,  201 

Tiger-beetle,  186 

Timpe,  237 

Toadflax,  56 

Tobacco,  species  of,  moth-pollinated, 
154 

Tomatoes,  228;   beetles  on,  185 

Tnrtricidse,  140 

Touch-me-not.  78.  80 

Trees,  deciduous-leaved,  223;  ever- 
green, 38-40;  red-flowered,  248; 
white  blossoms  of,  239;  wind-polli- 
nated, 20,  21,  24-28;  yellow-flowered, 
232 

Trelease,  140 

Triangulins,  186 

TrifoUum  pratense,  70 

Trillium,  162,  256 

Trumbull,  John.  190 

Trumpet-flower,  76,  77 

Tubes,  floral,  length  of,  121 

Tulips,  224,  228,  230 

Tupelo,  116 

Turtle-head,  56,  59;  wild  bumblebee- 
flower,  78;    nectar-guides  on,  65 

Twinflower,  18,  174 

Tyndall,  226 

Umbel ] if ersp,  242,  261,  262 
Urn-shaped  flowers,  64 
Utricularia  vulgaris,  19 

Vanda  cxrulea,  64,  136,  252 
Ventura,  California,  92 
Veratrum  viride,  227 
Verbascum,  194 


Verbena  hastata,  94 

Verbesina,  121,  242 

Veronica,  172,   serpyllifolia,  172 

Vertical  flowers.  60 

Vervain,  purple,  94 

Vespa  germanica,  104 

Vetch,  102,  122,  222;    color  change  in, 

56 
Viburnum,  180,  190,  194,  222 
Vicia,  Cracca,  56,  122;  Faba,  256 
Vincent,  267 
Vine-flowers,  202,  227 
Viola,    cucuUata,     110;      odorala,    252; 

rotundi folia,  48;  tricolor,  48 
Violet,  bee  of,  110;    colors  of,  64,  237; 

sweet,   252;    wild  blue,   48;     yeUow. 

48 
Vogt,  Carl,  70 

Waite,  265-267 

Wallace,  Alfred  Russel,  125,  206,  239 

Walnut-tree,  24,  202 

Wasp-flowers,  56 

Wasps,  47;  captured  by  spider,  104; 
punctures  made  by.  102 

Water-lilies,  yellow.  230;  insects  found 
on.  106.  108.  185 

Water-pollinated  plants,  223 

Water- tigers,  186 

Waugh,  270 

Weeds,  36,  38 

Weevils.  190.  192 

White  flowers,  150,  221-224,  236,  244,- 
common,  238;  clustered,  242;  indi- 
vidual. 244 

White.  Gilbert,  21 

Wieland.  224 

Willow-herb.  96 

Willows,  bee  on,  112;  conspicuousness 
of,  203;  pollen  and  nectar  vield  of, 
119;  pollination  of,  21,  23,  24; 
yellow  hue  of,  234 

Wind-pollinated  flowers,  202,  262; 
colors  of,  223;  hybrids  in,  277;  num- 
ber of,  36,  223 

Wind-pollination.  20-46,  223;  oldest 
method  of  pollen  dispersion,  46 

Winter.  William.  1 

Wisconsin,  bees  in,  120 

Witch-grass,  36 

Wood-betonv,  84 

Woodbine.  228 

Wood-borers,  190-192 

Wormwood,  227;  Roman,  38 

Xanthophyll,  228,  232 
Xenoglossa  pruinosa,  114 

Yellow  flowers,  172,  173,  221-224,  228- 

237;     color   variation    of,    236,    237; 

form  of,  232;    number  of,  232,  234; 

in  primitive  flora.  230  A 

Yucca,  moth-pollinated,  124,  140,  143k 

filamentosa,  143;    Whipplei,  140  ^^ 

Zinnia,  218;  elegons,  92  / 

Zygomorphous  flowers,  64  ' 


286 


311  HB" 

12/87/9B  41245 


\M^ 


